History Main / TheCorruption

* A very subtle application in ''Fanfic/DungeonKeeperAmi''. At first it seems to be merely the compromises Ami is forced to make - this AlternateDimension is a rough place, even when one doesn't have both the Villains AND the [[WhatTheHellHero Heroes]] after her. But slowly things like giggling in a creepy manner at inappropriate times, and clothing that spontaneously turns black and grows bat-motifs starts sneaking up on her...

[[folder:Real Life]]
* Methamphetamine abuse and addiction. For many users, the first few uses of methamphetamine provide great pleasure or greatly reduced need for things such as food and sleep, increased sex drive, and greatly increased focus and perceived capability - turning early users into work and sex machines. Unfortunately, the lack of sleep and the drug effect itself produces amphetamine psychosis and paranoia, the need for sex can make users make very unsafe sexual decisions, and addiction and tolerance means that more and more of the drug needs to be used to get the "good" effects - which increases the likelihood of the "bad" effects, and the human body is not capable of going without sleep and nutrition. Look up "faces of meth," or go to Website/{{Erowid}}'s meth vault to see what happens next.
** Before meth was discovered, some people used cocaine or its derivatives (such as the [[UsefulNotes/RedOctober Russian Civil War-era]] "Baltic Tea" (a solution of cocaine in vodka) for this purpose.
* Ketamine abuse. While, if somewhat managed in the short term, it can provide some short-term benefits (from the highs to proven effectiveness in some cases of depression and for pain management - both of which have been the target of serious medical studies), even ''moderate'' use beyond a very, very short term can become addictive (requiring at least small doses to stave off physical withdrawal), and can damage the bladder, liver, and urinary tract due to the drug's metabolization and being passed from the body as microscopic but sharp crystalline matter. Ketamine abuse can also lead to ''anhedonia,'' or the inability to feel pleasure from anything, as well as total disconnection from the ability to feel ''at all.''
* Tobacco use, in a far less immediately dramatic and more drawn-out way. Nicotine has some slight positive effects on performance and brain function as a mild stimulant (especially for existing addicts), and yes, to some, SmokingIsCool despite the efforts to discourage that trope - except, unlike the similar stimulant caffeine, it's far more addictive, has more direct effect on blood vessels, and likely slightly more carcinogenic than caffeine on its own. The major problem, though, is that it's usually consumed via smoked or chewed tobacco - which are the "dirtiest" consumption methods, with the tar and other chemicals in the burned leaves (and/or the tobacco-specific nitrosamines in chewing tobacco) slowly damaging every system in the human body - resulting in everything from lung cancer to damaged teeth and gums to heart disease to emphysema to impotence and more when the smoker hits their forties onward. Some studies have also shown that nicotine can deepen or worsen depression and anxiety, and anecdotal evidence shows that it becomes a form of self-medication for both at the same time, with immediate "feel better" effects but long-term worsening.
* Rabies works similarly to this trope - it causes an inflammation of the brain/meninges that leads to symptoms of "slight or partial paralysis, anxiety, insomnia, confusion, agitation, abnormal behavior, paranoia, terror, and hallucinations, progressing to delirium, and hydrophobia". Particularly for non-human mammals, these symptoms often lead to rabies spreading itself, since even ordinarily non-aggressive animals are made much more likely to bite or attack other creatures even when not in danger or hunting, thus infecting them as well. Their behavior is even eerily similar to victims of some examples of The Corruption in fiction, but, perhaps for the best, treating rabies is almost impossible without proper vaccination or emergency treatment, specially if the neurological symptoms are already showing. This means infected animals have a limited timespan to go around spreading the disease before succumbing to the disease.
* Institutional bigotry. Most people who lived back when racism, sexism, or other forms of discrimination were societally acceptable likely considered themselves to be moral and decent people, even if they did things like participate in lynchings. In general, most such people [[ApeShallNeverKillApe sincerely treated members of their own in-group much better than they treated minorities]], and did not see any contradiction, implying that, had they been born into a society that did ''not'' approve of such things, they wouldn’t have become monsters.
[[/folder]]

* At the end of season 4 of ''Series/{{Supernatural}}'', Castiel tells Dean that [[spoiler:consuming enough demon blood to kill Lilith will permanently mutate Sam into a monster. Possibly, God cleaning it out of his system prevented this.]]

* The Skeksis' abuse of the Crystal of Truth in ''Series/TheDarkCrystalAgeOfResistance'' corrupted it, and spread that corruption into Thra itself. The corruption, called "the Darkening", blights the land and drives living creatures into a mad frenzy at its touch.

* In Myth/GreekMythology, although intended as a punishment from which humanity would learn, the Miseries sealed in [[PandorasBox Pandora's urn]] wound up being this instead. They turned all of humanity save Deucalion and his family into irredeemable monsters. And thus, the GreatFlood.
* Mythology and Religions Researcher René Guénon called this Counter Initiation. According to him, all religions warned against this force and this force is the reason for the dark ages of humanity. (And that the biblical end times were all About this force rising to power.) Rudolf Steiner issued a similar warning and called it the "Ahrimanic Deception". Aleister Crowley called it the "black School of magic". Many later followers of Guénon, like Jean Parvulesco and Charles Upton, described the counter Initiation as an illuminati like AncientConspiracy.

[[folder:Anime and Manga]]
* ''Manga/{{Bleach}}'': Hollowfication is the insertion of Hollow reiryoku into a Shinigami soul and blending it with their original reiryoku to grant the Shinigami a massive power boost. However, the process also destroys their sense of self and eventually causes their soul to self-destruct [[spoiler:unless given a vaccination derived from Human and Quincy reiryoku]]. Those who survive the process can learn how to master their hollowfication by defeating the AnthropomorphicPersonification of their SuperpoweredEvilSide. [[spoiler:However, Quincies have no natural defense against hollow taint and will die unless given a vaccination of Human and Shinigami reiryoku.]]
* In ''Manga/{{Claymore}}'', being turned into a Claymore is much like this. In fact one of the requirements for being a Claymore is heroic will power, without it you lose control of the power and Awaken into an extremely powerful monster.
* ''Franchise/{{Digimon}}'':
** ''Anime/DigimonAdventure'': The Black Gears would cause any Digimon they possess to become berserk. Additionally, a memorable moment in ''Adventure'' was when Tai tried to force Greymon to reach Ultimate level so he could defeat Etemon resulting in Agumon digivolving into his corrupted Ultimate form, [=SkullGreymon=].
** ''Anime/DigimonAdventure02'': Greymon becomes [=SkullGreymon=] again when the Digimon Emperor captures him using a Dark Ring and tries to make him digivolve into [=MetalGreymon=]. After some tests with the newly improved Dark Spiral, the Emperor is able to make Agumon digivolve into a corrupted form of [=MetalGreymon=] called [=MetalGreymon=] (Virus). Ironically, it was later revealed that the Emperor himself was the victim of a corruption in the form of a Dark Spore.
** ''Anime/DigimonTheMovie'': Part 2 of the movie, a dub of ''Our War Game'', has a Digimon get infested with a computer virus which causes it to start causing all manner of chaos across the internet. Part 3 reveals that the virus has now found a new host in Kokomon, one half of a an American Digidestined's pair of Digimon twins.
** ''Anime/DigimonTamers'': Perhaps the most terrifying example of the corruption of a partner Digimon came in the form of Megidramon. When Leomon is killed by Beezlemon, Takato's rage causes Guilmon (who is already a virus type) to become a large, terrifying red dragon. What made Megidramon so terrifying is that he [[PersonOfMassDestruction could destroy the digital world just by ''existing''.]] Fortunately, Jeri was able to snap Takato and Guilmon back to normal.
** ''Anime/DigimonDataSquad'': The first time [=ShineGreymon=] mode changes, it was into Ruin Mode, a corrupted version of the true [[SuperMode Burst Mode]]. This occurred during [=ShineGreymon's=] battle with [=MirageGaogamon=] when Marcus' dark emotions, fueled by his belief that his friend Thomas turned on them and joined Kurata, caused [=ShineGreymon=] to go through Burst Digivolution. [=ShineGreymon=] Ruin Mode went out of control until it regressed back to Koromon's Digi-Egg.
* In ''Manga/{{Freezing}}'', the Stigma that grants the [[SuperSoldier Pandoras]] the amazing powers they use to fight against the [[EldritchAbomination Novas]] [[spoiler:is essentially ''Nova tissue'']]. The risk of the Corruption taking over a Pandora is actually pretty low since Pandoras only have a few Stigmas attached to them. [[spoiler:The people in charge of Pandora development came up with this policy after one Pandora with about ''twenty'' Stigmas fell victim to the Corruption and ''became a Nova''. This Pandora was the protagonist's ''older sister'', Kazuha. Since Kazuya has a similar "Stigma body" (the reason he can use "Freezing" without first forming a bond to a Pandora), Yumi Kim is concerned that he might suffer the same fate]]. [[spoiler:The Novas can also force the Corruption to take over the Pandoras by ''eating them''.]]
** [[spoiler: And now the people in charge want to see if the Corruption can be controlled and weaponized after the main character forced herself into Nova Mode and managed to bring herself back. Two Pandora veterans are horrified at this idea as they saw what happened to the aforementioned Pandora with the twenty Stigmas.]]
* Happens to Yomi in ''Manga/GaRei'' [[spoiler:at least a couple of times,]] because a [[MineralMacGuffin Sesshouseki]] possessed her.
* ''Manga/HoloearthChroniclesSideEYamatoPhantasia'': Stigma is a black miasma that appears from the negative emotions, periodically turning people BrainwashedAndCrazy and ruining the land. Continuous stress can make a person possessed by animal Ayakashi that matches their behavior.
* In ''Manga/KingOfThorn'', Medusa usually causes the victim to be TakenForGranite. However, in certain people it brings on other types of BodyHorror: a LovecraftianSuperpower at best, a OneWingedAngel at worst.
* An episode of ''Anime/KirbyRightBackAtYa'' featured the titular pink blob possessed by a corruption-inducing frog. The result was not pretty.
* ''Manga/MagicalRecordLyricalNanohaForce'' has the Eclipse virus (which is not TheVirus, despite its name), which grants the infected AntiMagic and insane [[HealingFactor regenerative]] powers, [[WithGreatPowerComesGreatInsanity at the price of slowly losing their sanity unless they regularly kill people]]. And that's only if you're lucky. Most people that are exposed to it just die.
* ''Anime/MagicalProjectS'' - Pixy Misa is a part of Misao that she's not aware of, and gradually is growing stronger. [[spoiler:After the BigReveal and a JourneyToTheCenterOfTheMind, they start to integrate.]]
* Dark chips in ''Anime/MegaManNTWarrior''.
* In ''Manga/{{Naruto}}'', the cursed seals, Sasuke's being a prominent example.
** [[ThePowerOfHate Hatred]] is also portrayed as this throughout the series, with the CycleOfRevenge being portrayed as a mix between a HatePlague and TheVirus.
* ''Manga/NegimaMagisterNegiMagi'''s BlackMagic seems to be like this, giving superpowers while slowly turning poor Negi [[spoiler: into a demon]], with side effects of acute magical poisoning from the negative emotions it enhances; the further the poisoning and transformation progress, the more the PowerIncontinence springs up. Played with in that he ''doesn't really mind'', citing that he's "too upbeat" for it to kill him with negative emotion poisoning, and he already knows at least one literal [[spoiler: NobleDemon]].
* ''Franchise/{{Pokemon}}'':
** In ''Manga/PokemonAdventures'', just touching the Red and Blue Orbs will potentially turn you mindlessly insane, and holding them for too long will cause you to become crazy psycho-killers under the control of Groudon and Kyogre, with the Orbs themselves fusing into your body. Ruby and Sapphire had to train their minds so that they would not succumb to this fate.
** A very similar thing happens in the ''Anime/{{Pokemon}}'' anime, too. The Blue and Red Orbs also absorb into whoever holds them for long enough. Pikachu becomes possessed by the Blue Orb, which causes him to go insane and electrocute everyone around him and obsess over helping Groudon defeat Kyogre. [[BigBad Archie]] also gets possessed by the Red Orb.
* The plot of ''Anime/PrincessMononoke'' begins when Ashitaka is attacked and infected by a corrupted boar-god. While WalkingTheEarth, he discovers that his infected arm has supernatural strength and a will of its own. It will eventually kill him.
* The Raven's blood in ''Anime/PrincessTutu'' grants those who are affected with it dark powers, but also twists their personality to be crueler and more selfish. Prolonged exposure ends with them [[spoiler:[[BodyHorror turning into anthropomorphic crows]] and being completely under the control of the Raven himself]].
* When a MagicalGirl uses her magic in ''Anime/PuellaMagiMadokaMagica'', her Soul Gem darkens. She must take a Grief Seed and use it to cleanse the gem, because if she doesn't, the Soul Gem will keep getting darker...[[spoiler:until it eventually darkens completely and becomes a Grief Seed itself, [[AndThenJohnWasAZombie resulting in the magical girl becoming a]] [[EldritchAbomination Witch herself]]. The worst part? No matter how long they do it, all magical girls will eventually fall to the corruption, becoming witches. Also, since the darkness in the Soul Gem appears to be grief, a Magical Girl who fails to cleanse hers will become gradually more and more desperate and broken until her eventual transformation]]. The only way to stop it? Either [[spoiler:die before this can happen]], or [[spoiler:use your wish to destroy the Corruption and ensure that no one has to become a Witch (this latter one requires phenomenal magical potential since it alters the very laws of the universe)]].
* An odd case in ''Manga/RosarioPlusVampire'': vampire blood injected into a wounded person will at first heal them and temporarily grant them vampiric powers, but repeated doses will begin to eat away at their [[BodyHorror body]] and [[WithGreatPowerComesGreatInsanity mind]]. The result [[OurGhoulsAreCreepier isn't]] [[HumanoidAbomination pretty]].
* In ''Manga/{{Shy}}'' the BigBad puts rings on people who force their wearer to bring out their deepest and darkest emotions like anger or self-loathing. They also materialize these emotions on the outside, making their hosts undergo a PainfulTransformation which turns them into a monster. Fortunately, the effects can be reversed if the ring is removed.
* The Black Blood is used in ''Manga/SoulEater'' to create an EldritchAbomination. It infects the [[DarkMagicalGirl Dark Magical]] [[AmbiguousGender (insert gender here)]] and the [[spoiler: two lead characters]], radically increasing their power and [[WithGreatPowerComesGreatInsanity risk of explosive insanity]].
** Strong manifestations of insanity such as powerful potential Kishin and Asura, the real deal, can even warp the minds of others. However, you're more likely to just hallucinate and be prone (or in [[SociopathicHero Stein's]] case, ''more'' prone) to acts of violence. Running into one of them, namely the Clown, is one of the possible explanations for the Face Heel Turn of [[spoiler:Justin Law]]. It is the first proper example of Stein's claim that "insanity is contagious" and that Asura's wavelength can corrupt previously normal people.
* Using magic in ''Manga/StraitJacket'' gradually turns the caster into a demon. The titular jacket is designed to prevent this from happening to demon hunters but isn't foolproof.
* In ''Anime/UmiMonogatari'', Sedna's influence is signified by too-bright or red eyes.
* ''Manga/{{Uzumaki}}''… good lord. The spirals are coming [[spoiler: to turn you into a snail...]]
** ''Manga/{{Gyo}}''. GYAAAAH. [[spoiler:you mean GASHUNK]]
* In the original ''Manga/YuGiOh'' manga, Zorc Necrophades (the FinalBoss of the Shadow RPG) is this to Thief King Bakura, Akhenaden, and anything that has a piece of his soul in it, as he will eventually consume and replace them. The spirit of the Millennium Ring "Dark Bakura" began as that of Thief King Bakura, but ended as Zorc.
** In the ''Anime/YuGiOh'' anime, half the people get corrupted in one form or another. The Seal Of Orichalcos is the best example, with it corrupting monsters even, giving them red eyes, an evil grin, and 500 extra attack points, and making the holograms real, among other things. Yugi plays the Seal during one match to force Yami out of the mental rut he'd gotten into in Yugi's absence.
** In ''Anime/YuGiOhCapsuleMonsters'', the Millennium Ring aided Alexander's thirst for power and drove him mad.
** In ''Anime/YuGiOhTheDarkSideOfDimensions'', the Millennium Ring brings out the darkness in Mani and Aigami's hearts, leading them to try and kill Ryo Bakura even after he explains that he didn't kill Shadi.
* The [[LightIsNotGood Light]] of [[NamesToRunAwayFromReallyFast Destruction]] in ''Anime/YuGiOhGX''. It's responsible for corrupting the big bads of season 2 and 3.
* [[ClingyMacGuffin Numbers]] do this to their owners in ''Anime/YuGiOhZEXAL''. Number Hunters need magical or technological aid to resist their influence (like the Emperor's Key in Yuma's case, or the Photon Transformation in Kaito's).
[[/folder]]

[[folder:Literature]]
* In ''Literature/TheBehemoth'', [[TheSymbiote the symbiotes]] are also a form of this. They are worm-like creatures possessing only a sense of touch and the ability to move slowly. When they crawl into a human body, though -- through a wound, the mouth, or the ear -- they merge with it, becoming a patch of mobile, bruise-colored flesh. It grants its host [[HealingFactor the ability to heal from almost any wound]], seeing into the [[DarkWorld Otherworld]], and gives the ability to undergo a [[BodyHorror painful and disturbing]] [[HenshinHero transformation into]] [[LovecraftianSuperpower a monstrous alternate form]].
* In ''Literature/DisAcedia'', the Poison, a substance produced by titular EldritchLocation, gives the consumer extraordinary power, but A is fueled by souls, and B eventually enthralls the user to Dis.
* In the ''Literature/DreambloodDuology'', once a Gatherer uses their powers to kill rather than to bestow peace, a long downward spiral of dreamblood addiction begins. If they even suspect they are emotionally unbalanced, they may ask to die.
* In ''Literature/TheDresdenFiles'',
** There are [[ThirtyPiecesOfSilver the Thirty Coins]], the Blackened Denarii. They are the very coins used to pay Judas Iscariot for his betrayal, and each one is now host to a bound Fallen Angel. They cannot affect the world until some mortal touches them, but at that point, a variety of unpleasantness can ensue. They are ''very'' corruptive, avatars of Hell on Earth.
** Also, in "Cold Days", we find a much more sinister form of corruption from [[spoiler:The Outsiders]] has affected some powerful magical beings.
** [[spoiler: The Fae Mantles]] also have this effect on their hosts, slowly changing them into their predecessors.
** Black magic can have this effect on warlocks. The more they use it, the more right it feels to use it. This is particularly true with mind magic. It turns out the Council's draconian "break any of the Laws of Magic and it's OffWithHisHead whether you had any way of knowing about the council or laws or effects of the spells you used" rules is because of that: use of certain spells invariably warps the mind of the user to the point that ''experience'' has told them it's "kill the user ''now'' or ''after'' they've racked up a massive body count."
* The main characters in ''Literature/EdenGreen'' become infected with an alien needle symbiote that makes them immortal and turns at least one of them dangerously insane.
* ''Literature/TheElricSaga'' of Creator/MichaelMoorcock demonstrates that if a human being draws closer to Chaos, their human form fades and disintegrates and they become progressively more beast-like. In the final battles, Chaos fields huge armies of beings who were once human but who are now beast-hybrids.
* The Shadow Plague from the ''Literature/{{Fablehaven}}'' series.
* In ''Literature/KeysToTheKingdom'', if Arthur uses the Keys too much, he will be permanently transformed into a Denizen, due to "sorcerous contamination".
** [[spoiler:According to the 6th book, he is past the point of no return. This could be considered CursedWithAwesome, however, considering that it helps him survive such events as getting shot in the side of the head and being dissolved by Nothing.]]
* The Rings of Power in ''Literature/TheLordOfTheRings''. The more you wear one, the more it corrupts you. Gollum was a normal hobbit once and the Ringwraiths were human kings. This only applies to the rings that Sauron helped make, however, and only to humans or closely related races like the hobbits. Dwarves are just too bloody stubborn to corrupt (they turn really greedy instead), while Sauron never touched the elven rings and they are thus not subject to his taint. [[spoiler: Tom Bombadil is immune to the ring's effects because he has absolutely zero interest in anything outside his little part of Middle Earth]]. The Ring was even a temptation to beings like Gandalf and Galadriel, who both implored Frodo ''not'' to offer it to them.
** This is likely why Gandalf wanted to recruit the folk of the Shire in the first place. Hobbits seemed very resistant to the effect, possibly due to their innocent nature. The Ring's effect on Bilbo was minimal (although it did make him the longest-lived hobbit in history) and Frodo was able to successfully resist its power until the climax of the story. [[spoiler: Even Gollum is shown still having a good side which can be coaxed out despite the extremely long time the Ring was in his possession.]]
* In ''Literature/{{Pact}}'', this is what separates demons from other supernatural beings, many of whom are equally malevolent, and leads to diabolists (demon summoners) being hated and feared. Demons generate a taint, explicitly compared to radiation, which affects those around them, and in turn spreads to those that they interact with. Depending on the specific nature of the demon, the effects can be different, but they can turn animals hostile around them and drive people to violence. The taint is near-impossible to contain or avoid, so diabolists tend to spread it as they go-and whatever the effects are are always detrimental to human life, if to varying degrees.
* ''Literature/ParadiseLost'': Gustav Doré's illustrations show Satan's progressive shift from FallenAngel to [[OurDemonsAreDifferent Devil]]. During the flashbacks he appears like a normal angel, albeit with DevilishHairHorns. In hell, his wings [[GoodWingsEvilWings molt and become batlike]], and on his way to earth he begins [[EvilCostumeSwitch removing his angelic armor]], [[FullFrontalAssault eventually stripping naked]]. By the end, he's JumpedOffTheSlipperySlope and become the traditional BigRedDevil in mind and body.
* The ''Literature/ParrishPlessis'' series has the Eskaalim parasite. It grants a bounty of powers to the infected: HealingFactor, FeelNoPain, VoluntaryShapeshifting, and more. By the time you've allowed it to advance that far, [[DemonicPossession you're no longer in the driver's seat]], and it's too late to do anything about it...
* In ''Literature/ThePrinceOfThorns'', the NominalHero Jorg gets wounded with a necromancy dagger, which gives him TaintedVeins and restricted Necromantic ability. In the second book, he learns that this corruption makes him less and less human and brings him closer to being assimilated by The Dead King, the most powerful necromancer who has already subjugated most others.
** Then, he gets a shard from a Fire Mage [[spoiler: Gog]] in his body and this ''also'' leaves him vulnerable to possession from Ferrakind, Dead King’s fire equivalent. [[spoiler: eventually he manages to deal with it by over-using both of his powers at the same time, which forced the two energies to fight against each other until they both got eliminated from his body.]]
* Night and darkness function as this in ''Literature/ShadowOfTheConqueror,'' turning any human caught in it for 24 hours or longer into a mindless creature of pure evil called a Shade.
* ''Literature/TheSisterVerseAndTheTalonsOfRuin'' has the blood of the Astral Lords, which grants anyone it's injected into rapid regeneration, but if they don't have anything stabilizing them, they are transformed into mindless bird monsters who live in constant, excruciating pain.
* ''Literature/TheStormlightArchive'': The Parshendi ''forms of power''. By accepting DemonicPossession, a Parshendi can assume several different forms that grant various supernatural powers (for example, stormform grants the ability to throw lightning and summon an Everstorm). But, as just mentioned, you have to be possessed by a bit of the Cosmic Principle Of Hatred to access these forms.
* In ''Literature/ThoseThatWake'', hopelessness corrupts people and lets Man in Suit influence and control them.
* ''Literature/{{Uprooted}}'': The Wood's magic infiltrates anyone it touches to turn them into a vessel with which to bring further beings under its sway. People in its valley live under constant threat of wolf bites infecting their cattle or even pollen blowing into their crops. Just passing under the branches can turn a good person into a murderer, lying and hypnotizing and warping them into something inhuman. There's a very short window of time to heal a victim before they [[KillItWithFire must be burned]]. Worse, the Wood [[IntelligentForest is devastatingly intelligent]] and works deliberately to keep the two countries it borders in a state of warfare to keep them weakened while it tries to KillAllHumans.
* ''Literature/TheVagrantTrilogy'': Infernal essence twists living flesh, dead flesh, and the land itself. However, it also goes the other way -- the world itself burns infernals, which is why they have to taint the land for every step they take. The Usurper can't travel much farther north than the Fallen Palace, while the Uncivil found a way to survive with a cloak of corpses, and the First spreads himself through humans and uses them as shields.
* In ''Literature/VoyagesOfTheFlyingDragon'' there’s the Wasteland Taint, which makes the earth ''itself'' look discoloured and diseased, and the air also gets infected until it gets to certain height above the ground. The only plants growing there become harsh and metallic, while all the animals become hollow and mindless versions of themselves, known as [[OurDemonsAreDifferent Demons]]. Humans simply get sick and die, however.
** Late in the first book, it is revealed that [[spoiler: Taint is the result of Earth’s power being depleted due to the industrial overuse of Elemental Bestia and is used by the Demon King to turn all other creatures against humanity]], which is likely why humans don’t survive to demonhood.
* In William King's ''TabletopGame/{{Warhammer 40000}}'' novel ''Literature/SpaceWolf'', the aspirants are warned they can become "wulfen", wolf-like creatures. One does. [[spoiler:Ragnar has to kill it. It [[DyingAsYourself speaks his name]] and dies. Only then does he learn it had been his best friend Kjel.]]
** In Lee Lightner's ''Wolf's Honour'', [[spoiler:all the Space Wolves]] are threatened by its taking over.
** In Creator/JamesSwallow's ''TabletopGame/{{Warhammer 40000}}'' ''[[Literature/BloodAngels Deus Encarmine]]'', many of the Blood Angels succumb to their "flaw" and begin to hallucinate that they are fighting the final battle between their primarch, Sanguinius, and Horus, and so become TheBerserker; all of them are tempted by it, every fight, though Rafen notices that this time, it struck with uncommon quickness, among veterans.
** In ''Deus Sanguinius'', at the climax, [[spoiler:Rafen succumbs to this; on the other hand, it does unlock the powers of the [[BladeOnAStick Spear of Telesto]] for him, and the daemon he fights is shocked to see that the many futures in which Rafen failed instantly vanish. Then the spear protects him. When the dying daemon unleashes it in the other Blood Angels, they terrify their enemies, who retreat although [[AttackAttackAttack they never retreat]], and the spear even lets Rafen bring back his battle brothers who had succumbed.]]
* Robert Jordan's ''Literature/TheWheelOfTime'' novels has a few examples:
** Mordeth lurks in the ruins of Shadar Logoth offering gifts to visitors, which will corrupt them with the genocidal madness that destroyed his city and lead them to infect everyone close to them.
** The Dark One occasionally "blesses" some of his followers with access to the True Power, a powerful destructive force which happens to be massively addictive and drives those who use it too often violently insane.
** While not inherently evil, ''saidin'' (male-accessible magic) was "tainted" by the Dark One in the backstory so that it can't be used without exposing oneself to the taint, inevitably driving male magic-users insane. Since magic in this setting is already somewhat addictive, and most people [[HowDoIShotWeb start off not realizing]] [[PowerIncontinence what, how or why weird things happen around them]], male channellers tend to wind up nutso relatively fast. The initial taint, when there were already hundreds or thousands of active, powerful male magic-users out there, caused [[ApocalypseHow the Breaking of the World]] when they all went nuts more or less at once, and for thousands of years afterward the Red Ajah (a sect of female magic-users) dedicated themselves to hunting down and forcibly de-powering male magic-users as they manifested themselves to prevent further damage. [[spoiler: In the course of the story the main characters manage to cleanse this taint, allowing men to once again use magic safely.]]
* In ''Literature/TsunTsunTzimTzum'', the spiritual corruption of Lilith is a constant danger to anyone who [[HeWhoFightsMonsters tries to fight her.]] Falling to it completely often requires a long process of increasingly dubious moral compromises and more and more depraved self-indulgences, but it can be hurried up considerably through BlackMagic that unleashes a person's worst impulses.
* The titular EldritchAbomination from H.P Lovecraft's ''Literature/TheColourOutOfSpace''. It's a sentient, malevolent radiation that affects people, plants, animals, buildings and even the very landscape. Fruits and vegetables are unusually large and take on a glossy appearance but taste disgusting and are possibly also toxic. Humans affected by the Colour last quite a bit longer than other creatures, but they usually go mad and later turn into... [[HumanoidAbomination things that definitely aren't human any more]]. All affected organisms eventually grow gray and brittle as if the Colour is literally sucking out their life force, until they crumble into dust under their own weight, [[AndIMustScream while still being alive and aware throughout]].
[[/folder]]

[[folder:Tabletop Games]]
* ''TabletopGame/{{Aberrant}}'', Creator/WhiteWolf's superhero RPG, had Taint. The explanation was that the human body, [[NinetyPercentOfYourBrain even with the extra lobe and all]], just wasn't suited to channeling the raw energies of the universe; channeling too much could affect your body in strange ways. It might start with glowy eyes and a strange timbre to your voice, but it would eventually grow into permanent stone skin, a short-range radiation effect... oh, and [[WithGreatPowerComesGreatInsanity insanity]]. Thing is, to get to the true "break the universe" levels of power, you ''had'' to take Taint...
* ''TabletopGame/BlueRose'' has an actual mechanic named Corruption. How does it work? If you get corrupted, the more corruption you have and the more debilitating effects your character suffers. Get too much and it will kill you. But you can embrace corruption, in which cause you instead get buffed. The more corrupted you are, the more POWER you have!
* ''TabletopGame/CallOfCthulhu'' may have been the original game to use this concept, with the Sanity score. The more you learn about the Cthulhu Mythos, the more effective a monster-hunter and magician you become... and the lower your Sanity drops until you eventually GoMadFromTheRevelation and join the forces of the old ones.
* In ''TabletopGame/ChangelingTheLost'', one possible fate for changelings (given the toolbox nature of the game) is to turn into [[spoiler:[[TheFairFolk True Fae]] as they reach the zenith of their power (which is inevitably followed by the nadir of their [[KarmaMeter Clarity]]).]]
* Eden Studio's ''TabletopGame/ConspiracyX'' has the "Seepage" phenomenon, which occurs from dealing with the supernatural. When it corrupts a character, they start going insane. [[spoiler: Continued exposure to seepage will at best turn your character into a babbling wreck, [[HeWhoFightsMonsters at worst it turns them into one of the things they were hunting.]]]]
* ''TabletopGame/DarkHeresy'' has this as a game mechanic called [[ExactlyWhatItSaysOnTheTin Corruption Points]]. If you accumulate too many, you start to mutate...
* In ''TabletopGame/TheDresdenFiles RPG'' players have to spend precious refresh points to gain new abilities, and when the refresh rate hits zero the character becomes so corrupted by power that they become unplayable. Interestingly, these abilities need not be supernatural and are sometimes forced upon characters who act in certain ways. A wizard breaking one of the laws of magic, for instance, must buy the Lawbreaker ability.
* The ''TabletopGame/DungeonsAndDragons'' 3rd edition sourcebook ''Oriental Adventures'' featured "Taint" as an effect of spending time in the [[{{Mordor}} Shadowlands]] or interacting with its natives. It came back as a setting-generic version in the 3.5 supplements ''Unearthed Arcana'' and ''Heroes of Horror'': Taint slowly corrupts anyone who stays in a tainted area, performs evil actions, or is unlucky enough to fight a monster with the ''bestow taint'' ability. As your Taint score climbs, you [[ThisIsYourBrainOnEvil go mad]], endure [[BodyHorror horrific transformations]], shift alignment to evil, and eventually turn into either a psychotic killer or a psychotic killer ''monster'', at which point you roll up a new character.
** ''Heroes of Horror'' even includes Prestige Classes with a Taint Score requirement. They are all either about embracing corruption or accepting that its destructive power is inevitable -- but not going down without a fight.
** ''TabletopGame/{{Ravenloft}}'' has Powers checks: every time a character does something sufficiently wicked to call the attention of the [[PowersThatBe Dark Powers]] of the demiplane, they may reward him with a special ability, which only serves to accelerate his damnation. Fail enough Powers checks to commit an [[MoralEventHorizon Act of Ultimate Darkness]] and you end up a mockery of your former self, trapped forever in a domain of your own making.
* The Exsurgent virus family in ''TableTopGame/EclipsePhase'' is both this and TheVirus. Different strains can infect computers...or flesh...and the result is never, ''ever'' pretty, usually featuring BodyHorror and ''always'' featuring MindRape. Oh, and they're very, very adaptive. Like, normal-viruses-on-crack adaptive. A digital strain can infect a [[MatterReplicator nanofabricator]], reprogramming it to produce [[BodyHorror biological]] and [[GreyGoo nanotechnological]] variants, which then go on to infect other beings and devices. Oh, and it can also be transmitted as pure sensory information, so you can get infected just by watching the [[BrownNote wrong video]], known as a basilisk hack. It comes in many variants, but as a rule, infection with any strain of Exsurgent is a death sentence. The Haunting and Mindstealer strains mentally convert their victims into pawns of the virus over the course of months and minutes, respectively, imbuing them with mind-breaking [[PsychicPowers mental]] [[RealityWarper abilities]] and alien motivations. The Xenomorph strain acts much the same as the Haunting strain, but it transforms the victim's [[BodyHorror body as well]]. The only (relatively) benign strain is Watts-[=MacLeod=], which confers PsychicPowers without any overt downside. Nevertheless, these infectees often begin having dreams of alien landscapes, strange urges and feelings, and even a sensation that something else is looking out from behind their eyes...
* [[Creator/HPLovecraft Fittingly]], this is a major part of ''TabletopGame/EldritchSkies'': [[HyperspaceIsAScaryPlace Hyperspatial Exposure]] allows one to tap into PsychicPowers and FunctionalMagic at initial infection. Higher levels cause hallucinations, increased attention from the {{Eldritch Abomination}}s that live in hyperspace, and BlueAndOrangeMorality. Maximum levels cause [[BodyHorror horrific]] [[WasOnceAMan mutation]], and at that point, [[TragicMonster you can't reverse it]].
* ''TabletopGame/{{Exalted}}'' has three examples, which, [[GreyAndGrayMorality in true Exalted style]], has only one that is played straight.
** The Wyld, [[ChaosWorld the unformed elemental Chaos that is the foundation of all things]], has a tendency to mutate unprotected individuals, resulting in bizarre hybrids of man, animal, and [[TheFairFolk Raksha]]. While it ''does'' have an effect on people's minds-it's [[ThisIsYourBrainOnEvil addictive]], and it tends to simplify people's personalities so that they're more literary character than man-the first is (usually) curable and the second is mostly an InformedAttribute.
** Desecration, the [[AbusivePrecursors Yozis']] power to modify humans and animals into [[OurDemonsAreDifferent forms more to their liking]]. This does ''not'' have an effect on minds unless the Charm causing it is [[CharmPerson supposed to be doing that]], and for the most part, it's willing (although in the case of Cecelyne doing it, [[JackassGenie "willing" is a matter of semantics]]).
** The ''straight'' one is Gremlin Syndrome, a sort of pseudo-cancer derived from the Primordial Autochthon's sickness. See NightmareFuel for an explanation..
* This is the nasty downside of using [[{{Magitek}} arcanowave technology]] from ''TabletopGame/FengShui'', which is made of demons and BlackMagic. Every time you use it, it sends bent magic into your system like a virus. If you use it too much, you start mutating into something horrific and run the risk of becoming an Abomination, one of the altered demons that the Buro, the government of the 2056 juncture where this technology hails, uses to fight its wars.
* In ''TabletopGame/GeistTheSinEaters'', Sin Eaters turn into {{Meat Puppet}}s if they come BackFromTheDead one time too many,.
* ''TabletopGame/{{GURPS}}'' provides ways of modelling the trope:
** Some character disadvantages are worth some number of [[PointBuy character points]] in proportion to the evilness of whatever's corrupting you this week.
** ''GURPS Magic'' has rules for corrupting BlackMagic. ''GURPS Thaumatology'', a big book of variant magic systems, generalises these for all kinds of “spirit-assisted” magic. ''TabletopGame/GURPSThaumatologyAgeOfGold'', a setting which features multiple types of magic, includes instances of that type. In fact, one of the sample villains detailed, The Jungle Madness, is an example of where this leads; once a Central American sorceress, she is now a totally inhuman and dangerous supernatural creature.
* The [[DemonicPossession Possessed]] (from ''TabletopGame/{{Inferno}}'') turns into the embodiment of their Demon's Vice, and so on.
* In ''TabletopGame/LegendOfTheFiveRings'', the Shadowlands is a vast wasteland infected with the evil of the hellish realm of Jigoku. Prolonged exposure to this evil realm infects living things with the Shadowlands Taint. Even the slightest scratch by anything in or from the Shadowlands can infect someone. The Taint causes increased strength, speed and reflexes along with psychological changes such as violent outbursts and paranoia. Even when killed, a Tainted body often becomes re-animated as a zombie. What few 'cures' exist are usually fatal and are more concerned with the well-being of one's soul than one's mortal body.
** To a lesser extent, many of the spirit realms have their own versions of the Taint, referred to as "Control," on those who visit them for an overly long time. Taint is merely the most famous, but you can also end up with animal traits, or afflicted with a strange sense of mental chaos and prankster-ness.
** The touch of the Lying Darkness also qualifies. Its effects can be incredibly powerful, allowing you to hide more effectively in the shadows and perform increasingly powerful darkness-related feats. However, in exchange, you lose your identity bit by bit, until you're [[TheBlank faceless and have forgotten who you truly are.]]
** Recently, madness has become another example, at least in the card game. The influence of the Mad Dragon P'an Ku has manifested itself in a few different ways in the card game - most prominently, the Fallen Keyword indicates a figure under the influence of madness (though in some cases these were [[StatusQuoIsGod hallucinatory versions from the dreams of P'an Ku IF he wasn't stopped]]) and Madness tokens, which could have various effects and lead to other such effects.
* This is generally how ''TabletopGame/MagicTheGathering'' treats Phyrexia, especially while its remnants invade and warp Mirrodin.
** The Eldrazi have their own take on [[http://magiccards.info/query?q=eldrazi+conscription&v=card&s=cname this.]]
* [[CrapsackWorld Nearly every single gameline]] in the ''TabletopGame/NewWorldOfDarkness'' has Corruption in one form or another. Losing Morality is also a bit like this. You're less and less constrained by Morality as it falls, but if you hit zero, your character becomes [[NonstandardGameOver unplayable.]] In fact, the Corruption is ''the'' gimmick of [[CorruptCorporateExecutive Cheiron Corporation's]] [[TabletopGame/HunterTheVigil Hunters]]: they graft monster parts into their body. {{Squick}}.
** The protagonists of the ''TabletopGame/OldWorldOfDarkness'' game ''TabletopGame/DemonTheFallen'' have Torment, the spiritual residue of millennia in Hell. It afflicts all Fallen to some degree and can be used to supercharge a demon's powers, but doing so involves letting more Torment into your soul. It also acts as the game's KarmaMeter: too much Torment turns you into a monster like the [[EldritchAbomination Earthbound]].
** Wyrm taint in ''TabletopGame/WerewolfTheApocalypse'' corrupts a character's body and mind if left untreated. Gaia factions have rites for cleansing mild Wyrm taint, but severe Wyrm taint may necessitate an ordeal in Erebus.
** ''TabletopGame/WraithTheOblivion'' has Angst, the fuel that feeds the soldiers of Oblivion. As each wraith has a [[EnemyWithin Shadow]] in the back of their head beckoning them to give in, any act that feeds said Shadow (calling on its powers, following its advice, allowing it to take over temporarily and wreak havoc) allows it to accrue Angst. Once it hits permanent Angst 10, the wraith falls and becomes a Spectre.
* Flux works a little like this in ''TabletopGame/PrometheanTheCreated''. It is the antithesis of the creative power Azoth, waiting for a Promethean who has become disenchanted with the Pilgrimage to stumble upon it. Its trademark "gift" is mutation, slowly turning the user into an inhuman form, though it also grants control over Pandorans, its "children". Prometheans refer to the slow dive into irretrievable Centimani as being "seduced by Flux".
* ''TabletopGame/PrincessTheHopeful'' has Dark Warping. Once a character becomes Darkened by suffering a Breaking Point inside a Tainted Area (or just spending too long in one), then every time he loses Integrity he has a chance to gain a new Umbra. Each Umbra grants a power, but it also comes with a hefty downside, often hideous deformation or something else that makes human interaction more difficult. On top of that, being Darkened blights the conscience, making Vice more emotionally rewarding and Virtue less, and making it easier to lose Integrity at Breaking Points. And if your Integrity hits zero while you've got at least one Umbra, you die and a bestial Darkspawn is born from your corpse.
* In both D6 and D20 versions of ''Franchise/StarWars'' the RPG, [=PCs=] could acquire Dark Side points by using the Force for aggression or by committing evil acts. In the D6 version, [[NonPlayerCharacter acquiring too many made you lose your character.]] In the D20 version, it [[PoisonMushroom eventually reduced your stats]].
** In both d20 versions you can also lose a character with too many Dark Side points if the GM wants to run a light sided campaign, it's mentioned briefly in both rulebooks.
** The ''Dawn of Defiance'' campaign has this as a rule. You cannot be dark side, period.
* ''TabletopGame/{{Warhammer}}'' and ''TabletopGame/Warhammer40000'' bring us [[AlwaysChaoticEvil Chaos]], possibly the most developed and frightening example to date. It's ruled by the [[FourIsDeath four]] gods of mutation, plague, debauchery, and bloodshed.
** And when we say most developed, we mean ''most developed''. ''The Warhammer Fantasy Roleplay'' has a whole book on chaos taint, Tome of Corruption, including a ''D1000'' table for rolling up mutations, many of which have D10 to D100 tables of their own -- of which 80% are a direct death sentence for your character either because they make him [[AndIMustScream unable to live]] or because of the [[KillItWithFire reactions of society.]] But it's certainly nice to have those tables... It says something about how nasty Tome of Corruption is that ''TabletopGame/BlackCrusade'' is actually LighterAndSofter, lacking pretty much all of the "Gotcha!" mutations, like Mindless, Chaos Spawn, [[{{Cephalothorax}} Walking Head]]...
** Background material establishes that mutation will occur faster or slower based on which god a mortal worships primarily. The followers of Tzeench (the Lord of Change) are most prone to bizarre mutations (the Thousand Sons Legion became haunted suits of PoweredArmor trying to ''avoid'' Tzeench's mutation). Followers of Nurgle (God of Plague) are guaranteed to be wracked with numerous diseases constantly (The Plague Champion in ''VideoGame/DawnOfWar II'' even mentions that his body is ''liquifying!''), while followers of Slaanesh (Prince of Excess) and Khorne (the Blood God) mutate more slowly.
** Warpstone is Chaos energy solidified into crystalline form, so while it's still as corruptive as true Chaos, it can also be used as GreenRocks by those blessed with either ignorance, a good sense of denial, or a willing embrace of Corruption.
* ''TabletopGame/YuGiOh'':
** "The Fool" grabbed a random magical terminal seeking power, but ended up accessing "Spellbook of the Master", a high-level "Spellbook" that brings out anything in a Magician, ranging from their best to their worst. However, he unleashed and was consumed by extremely wicked magic inside "Spellbook of the Master", corrupting and transforming him into "Reaper of Prophecy". As a result, he went on a rampage.
** From [[Metaplot/YuGiOhHiddenArsenal the Hidden Arsenal storyline]], Cairngorgon, Antiluminescent Knight may be intended to represent the state of Gem-Knight Crystal after the final battle against Gishki Zielgigas and Evilswarm Ouroboros. With Sophia, God of Rebirth defeated, the united Gem-Knights' transformation into Gem-Knight Master Diamond beginning to fall apart. In the midst of this, Crystal appears to have been corrupted by the remnants of the Evilswarm virus and has either taken control of Diamond's crumbling body or reassembled his damaged body using the remains of his fallen comrades.
*** This in turn gives birth to the force behind the Shadolls, who are themselves a form of The Corruption.
** Gishki Psychelone is an Verz/Evilswarm-infected Gishki Noelia.
* In ''TabletopGame/{{Mythender}}'', Corruption is technically how much you ''appear'' like a god, while Fate is how close you are to actually ''becoming'' a god. (and yes, that's a bad thing; gods in ''Mythender'' [[JerkassGods ain't the cuddliest]]) The more Corruption you have, the easier it is to acquire more Fate, though, and you usually acquire both at the same time anyway.
[[/folder]]

[[folder:Video Games]]
* In ''VideoGame/AncientDomainsOfMystery'', the BigBad are the forces of Chaos, very similar to ''TabletopGame/{{Warhammer}}'' and ''TabletopGame/Warhammer40000'', including the corruption. There are several sources of corruption, including background chaos radiation which grows stronger as you approach the source ([[spoiler:The Chaos Gate]]). Corrupted monsters may turn into writhing masses of primal chaos. A corrupted player will gain additional powers and be a writhing mass of BodyHorror. Corruption-removal methods are the most sought-after thing in the whole game, because getting the full set of corruptions means you're close to an unavoidable NonStandardGameOver. And because some of the corruption side effects are really, really bad for your character. For instance, you can be drastically slowed down, instantly drain every magic wand you touch, poison everything you handle (including your own food and potions), and worst of all is the "unholy aura" one; everyone you meet, including powerful [=NPCs=], will become hostile at the mere sight of you. However, some corruptions [[CursedWithAwesome grant you useful powers]], and for several of the special endings, you need to be corrupted almost to the point of dissolution.
* Ladies and gentlemen, we have a powerful, unpredictable magic known as Chaos in ''VideoGame/AdventureQuestWorlds''. Chaos is a virus-like magical energy that can chaorrupt (short for chaos corrupt) objects and beings, and can also control their minds, making them BrainwashedAndCrazy. This viral magic is controlled by the BigBad, Drakath, and his CoDragons, the 13 Lords of Chaos.
** Ledgermayne, the seventh Lord of Chaos, is chaos magic personified. To be fair, it was just a mass of mana floating in the Para-Elemental Plane of Magic when Drakath's chaotic influence gave it self-awareness. So much that Ledgermayne was uncontrollable, even by its own TrulySingleParent.
** There's also the Chaos Shaper class, which players can buy after having had 15 months of membership in total. It lets them use the power of Chaos to land unpredictable effects on either themselves or their targets.
** Within the wider ''Creator/ArtixEntertainment'' {{Multiverse}}, there is the [[DarkIsEvil Shadowscythe]]: a vast and loosely organized group of pure Darkness elementals who see the other seven elements, particularly Light, as a taint or pollution, and so want to restore the perfect darkness that came before by "cleansing" the various iterations of Lore. One part of this agenda includes binding themselves to weapons or machinery and making [[DealWithTheDevil Faustian bargains]] with sentient beings in order to enslave or manipulate them into acting as their agents.
* In the Microsoft Excel-based ''VideoGame/ArenaXlsm'', this role is fulfilled by the literal Evil. After [[spoiler: The Emperor dies and his death frees The Ultimate Evil]], most of the enemies from there and to the end are the much stronger "Evil" versions of the earlier enemies.
* [[http://armello.wikia.com/wiki/Rot_(stat) Rot]] in ''VideoGame/{{Armello}}'', a disease usually contracted by being defeated by Banes. It causes the character to slowly go mad, and sometimes gain bonus dice against less corrupted characters. Notably, the king has a bad case of the Rot that increases each round and lowers his health until he dies, and the resulting madness is why the players are all trying to kill him.
* The Gohma in ''VideoGame/AsurasWrath'' are stated as being corrupt impure beings that take the form of rocky and [[MagmaMan lava-like]] animals. The strongest of them all are planet sized and can easily destroy planets casually, and nearly destroyed mankind. It took the combined power of Asura and the other deities to defeat them the first time around, but are hinted at making a comeback. [[spoiler:It does, and the only way it is stopped is by Asura once again, who crushes the very essence of its core.]]
* The world in ''VideoGame/TheBannerSaga'' is being consumed by this. In ''VideoGame/TheBannerSaga3'', half of the narrative is spent controlling a group going through the afflicted lands, where they have to fight Warped versions of the normal enemies.
* Seithr in ''VideoGame/BlazBlue'', a toxic substance spread over the world by the [[EldritchAbomination Black Beast]] when it attacked the world 100 years ago, renders most of the surface inimical to most life. Humans were forced to live in cities built at high altitudes to avoid succumbing to seithr poisoning. It's the Corruption since seithr is also the source of the setting's magic. The [[FunctionalMagic Ars Magus]] and [[ArtifactOfDoom Nox Nyctores]] used by most of the characters absorb seithr from their surroundings in order to use their abilities. The Kaka clan, including [[CatGirl Taokaka]], are able to tap into the seithr naturally with no apparent ill effects.
** And then there's the Azure Grimoire, the most prominent ArtifactOfDoom in the series. Like the Nox, it also runs on seithr to function, unlike them however, it is a remnant of the aforementioned Black Beast and using it will slowly corrode the user's soul into another beast, and injuries through supernatural means are retained across timelines.
* In ''VideoGame/{{Bloodnet}}'', your hero is a vampire who has an instant-kill bite attack, but each use of it decreases his humanity a little and brings him closer to the NonstandardGameOver (in addition to the [[InUniverseGameClock normal decrease of his humanity with time]]).
* Before the beginning of ''VideoGame/BloodOmenLegacyOfKain'', Nupraptor inflicted an insidious mental and spiritual "disease" on the entire Circle of Nine. This corruption tainted the Pillars of Nosgoth, and to restore them, the Circle had to be purged.
* Django gaining the ability to [[spoiler:turn into a vampire]] in ''[[VideoGame/{{Boktai}} Boktai 2]]'', [[GameplayAndStorySegregation at least storywise]], has him completely lose control of himself and operate on instinct whenever he uses it, and has him at constant risk of losing himself to it permanently. Using the ability too many times will land you with [[MultipleEndings a worse ending]].
* ''VideoGame/TheBreach'' has the Yellow, claimed to be another dimension of sorts, although the exact details aren't clear. What is clear is that all people that are afflicted with it firstly die and become traditional zombies, then mutate further into all manner of creatures.
* Ryu's "Dragon Mode" in ''VideoGame/BreathOfFireDragonQuarter''. The corruption accumulates slowly over the course of the game. If it reaches 100%, your game ends. [[spoiler:Which you'll have to do for the final battle, anyway, ironically]].
* ''VideoGame/CliveBarkersUndying'': The undying curse. Not to mention just being near the Scythe of the Celt can cause someone to descend into bloodlust and madness.
* In ''VideoGame/CorpseParty'', we have have the "darkening," in which the souls of anyone who completely loses hope of surviving in Heavenly Host Elementary are corrupted. Anyone afflicted with it essentially becomes an empty husk, rendering them beyond saving.
* In ''VideoGame/DarkEarth'', your character Arkhan is poisoned by a face full of liquid evil while on his very first day on his new job as a Guardian of the Flame, and starts to mutate into a creature of the Dark. You must help him find a cure before the transformation is complete. While one side-effect of the mutation is a [[TookALevelInBadass Level of Badass]], the more you use it, the more the mutation takes hold. When the mutation reaches 100%, you get a [[NonStandardGameOver Non-standard Game Over]].
* The Technocyte virus in ''VideoGame/DarkSector''. The only reason that the protagonist has not gone insane is that because of a pre-existing condition, he cannot feel the pain that drives all other infected mad.
* ''VideoGame/DarksidersII'' features Corruption, a force that can infect not only the living, but even [[spoiler: the automatons of the Makers.]] The Corruption is ultimately [[spoiler: destroyed throughout the universe when Death kills Absalom, the source of all Corruption and formerly the leader of the Nephilim that Death and the other Horsemen betrayed long ago to stop their universal genocide, [[ThePowerOfHate resurrected by his undying hatred for all Creation]] and [[CainAndAbel especially his brother Death]].]]
* ''VideoGame/DarkSouls'' has the Abyss. Most people who enter it simply die, but those who survive are driven violently insane and beyond reason, and often come out barely looking human anymore. Which is ironic, considering [[spoiler:the Abyss was spawned from concentrated Humanity. Whether this is an inevitable consequence of Human power growing too great or if this is simply what happens when you can't control it properly is left ambiguous.]] The final DLC of the ''VideoGame/DarkSoulsIII'', "The Ringed City", reveals the truth. [[spoiler:The Abyss was originally a source of power that Humanity could tap into via the Dark Soul with no ill effects. The Pygmy Lords who led Humanity were masters of the Dark Soul who aided the gods of Anor Londo in their war against the Everlasting Dragons. But the paranoid Gwyn feared the Dark Soul so much he trapped the Pygmies in the eponymous Ringed City and placed a seal of fire on Humanity to prevent them from tapping into the Abyss. This seal weakened over time and became ''the Dark Sign''. Bereft of the Pygmies' knowledge and hampered by the Dark Sign, Humanity could no longer tap into the Abyss properly, leading many to be deprived of their Humanity (becoming Hollow) and others to become mutated monstrosities as the Abyss flooded and consumed them.]] This had detrimental effects not just on Humanity but on the rest of the world as well since [[spoiler:the Dark Sign was empowered by the First Flame that provided light and life to the world. This caused the First Flame to flicker and eventually permanently go out.]]
* ''Franchise/DragonAge'' has the Taint, a disease/curse spread by Darkspawn blood. There's also the Blight, a physical manifestation of the taint upon the land, which spreads whenever they come up to the surface. It twists and corrupts all living organisms, mutating creatures into abominations such as blight wolves and ghouls (assuming the creatures manage to survive the initial phase of the infection in the first place). With each passing day, a blight grows, the earth itself withers and dies; the land is leeched of moisture, turning everything dry and brown. The sky fills with rolling, black clouds that block out the sun, making it easier for the darkspawn to surface. As this wasteland spreads, the corruption of the blight spreads with it, diseasing all in its path. And by "all" we mean "all"; as in, the corpses won't rot properly because ''even the bacteria responsible for decomposition are killed off''. What makes it the Corruption is that [[spoiler:Grey Wardens give in to it by drinking Darkspawn blood. This lets them sense Darkspawn, kill Archdemons permanently and avoid Ghoul-dom, at the cost of killing them a few decades later.]]
** The Brood Mothers take this a step further: [[spoiler:Human, elf, dwarf and qunari women are captured by the Darkspawn and force-fed Darkspawn blood. In order to survive they have to give in to the urge to eat the others which drives them mad and turns them into Brood Mothers]]
** [[spoiler:In the Warden's Keep DLC of ''VideoGame/DragonAgeOrigins'', an old human mage does the most ingenious thing: he ''weaponizes'' the taint, creating an elixir which can give the player tainted blood-based powers. It's not pretty, ethical (or ''sane'' for that matter), but they are incredibly useful.]]
** It got worse in the ''VideoGame/DragonAgeII'' DLC "Legacy" with TheReveal that [[spoiler:Wardens don't die, but simply turn into ghouls when they hear the Calling. There is no avoiding ghoul-dom once the Taint enters a person's body and the Warden's unique version of the Taint simply delays the effects from becoming apparent by a few decades, hence why the Senior Wardens prefer to go out in a blaze of glory against the Horde before this happens. Larius, a former Commander of the Grey, was unlucky enough to survive long enough to turn and is now basically ''ignored'' by the Darkspawn.]]
** There's also Red Lyrium, a variant of [[GreenRocks Lyrium]] that can infect people and turn them into horrific monstrosities, with similar effects on their sanity. [[spoiler:It is revealed in ''VideoGame/DragonAgeInquisition'' that Red Lyrium is actually Lyrium that has been infected by the Blight. The person who discovers this points out that the Blight can only infect organic materials, so the very existence of Red Lyrium proves that Lyrium as a whole is [[GeniusLoci alive]].]]
** [[spoiler:The Wardens]] use of the Taint backfires horribly in ''Inquisition'' when an unbelievably ancient and powerful Darkspawn binds most of them to his will through it.
* ''Franchise/TheElderScrolls'':
** The Corprus Disease in ''[[VideoGame/TheElderScrollsIIIMorrowind Morrowind]]'', developed using the divine power of the still-beating heart of a dead god by deranged PhysicalGod BigBad Dagoth Ur, kills plants, turns animals homicidal before slowly killing them, and mutates people into [[BodyHorror horrible, cancerous monstrosities]]. He can communicate with those it has infected via subliminal messages in their dreams, turning them into his {{Mooks}}. It also comes with some [[BeneficialDisease positive qualities]], such as [[TheAgeless no longer aging]] and [[IdealIllnessImmunity being immune to all other diseases]], but those infected are typically too deranged and mutated to enjoy them. [[spoiler: Naturally, the PlayerCharacter is infected during the main quest, but takes an experimental "cure" for the disease. It is explained by the cure-giver that the PC still has the disease, but the ''negative'' effects have been cured, leaving only the positive effects]].
** ''[[VideoGame/TheElderScrollsOnline Online]]'':
*** Lurchers are Spriggans ([[WhenTreesAttack tree-like]] PlantPeople with a GaiasVengeance tilt) who have been corrupted by "dark magics." The Spriggan's tortured spirit remains trapped inside the corrupted creature until it is slain.
*** Daedric Titans are corrupted [[OurDragonsAreDifferent dragons]] created by [[GodOfEvil Molag Bal]], the [[OurGodsAreDifferent Daedric Prince]] of [[NamesToRunAwayFromReallyFast Domination]] and [[TheCorrupter Corruption]]. Titans possess similar anatomical features and abilities as dragons, but were created in mockery of true dragons (who are [[OurAngelsAreDifferent Aedric]] in nature) and serve the Daedric Princes.
*** Grievous Twilights are [[BatOutOfHell Winged]] [[HarpingOnAboutHarpies Twilights]] which have been corrupted by Molag Bal. They are much more bestial looking and use TeleportSpam when attacking.
* The genetic code of the monsters in ''VideoGame/{{Evolve}}'' serves as this. Kala injected herself with a small amount, only for it to mutate her arm and face, while influencing her mind. Even with an artificial immune system booster the monster portions are spreading, with Caira giving her 14 days before she is overwhelmed. In the meantime she is susceptible to the monsters mental influence, causing her to scream out their thoughts when downed and mutter in her sleep.
* ''VideoGame/FinalFantasyXIV'' has the ''Shadowbringers'' expansion, which shows a world corrupted by purest [[LightIsNotGood Light.]] It also has some of the purest BodyHorror moments in the entire game, even in a game where one of the earlier dungeons involved a boss which was the severed, mutated head of a madwoman's dead fiance.
* Imulsion in ''VideoGame/GearsOfWar'' infects anything organic that it touches, and gradually mutates it into a "lambent" form.
* In the first few ''VideoGame/DotHackR1Games'', the ones where Kite was the protagonist, Kite has an ability called Data Drain (which causes the enemy to be weakened to a point where they are pretty easily killable) but using it causes Kite to risk infection from a computer virus, the very same virus that created Data Drain no less. If the infection reaches 100% then it's game over (the Data Drain is necessary to kill certain bosses in the main quest, but no infection is received from those bosses. It's also required to get "cores" which unlock story levels). In fact, as the % goes up, there's always a slight (increasing) chance of getting a game over. Not using it reduces the number.
* In ''VideoGame/{{Iconoclasts}}'', clumps of strange blue eyes appear soon after leaving The Tower. They are harmless...until they sense a sufficiently weakened target, and latch on to it to control it. The first such encounter is with Possessed Thunk, where a clump of these had colonized One Concern's Kerthunk mech, and [[spoiler:controlled the Silver Watchman, with an eye going over his face, and strings connecting it with the rest of the colony]].
** Afterwards, they [[spoiler:latch onto Agent Black at the end of her fight with Robin and Royal, she was being torn apart by the Isi seeds blooming inside her. Their effects allowed her to be "reborn" as an enormous screaming creature with the body made of Ivory trees, forcing Robin to kill her again... and again, as the "core" of that Ivory Beast separates and desperately tries to scale the rocket for one last time]].
** Lastly, these blue eyes have taken over all the creatures in the [[spoiler:Star Worm's Impact Zone]], turning them invulnerable to damage until Robin can get them off. Their origin is never explained outright, but it seems that [[spoiler:they are something produced by the bird species Star Worm's pilot belonged to, whether naturally or technologically. They were the means through which both the Omega Controller and the Star Worm itself were commanded, and when the eye was destroyed, the Star Worm ultimately killed the pilot on its own, rather than that being a simple failure of the controls]].
* Dark Eco in the world of ''VideoGame/JakAndDaxter''.
** The Dark Makers in ''VideoGame/Jak3Wastelander'' were once [[spoiler: Precursors]], but they were twisted by their exposure to it.
** Jak fights against his own corruption in ''VideoGame/JakIIRenegade'' after being pumped full of it by the Baron.
--->'''Oracle:''' I sense there is a dark rage burning within you, and in time, it will destroy you with its madness. Only the last power of the Precursors can save you.
* In the ''Franchise/KingdomHearts'' series, [[CastingAShadow the power of darkness]] is a dangerous, corrupting influence on anyone who channels it. It draws out the worst in a person, like rage or envy, and drives them to more selfish actions. Drawing too much on darkness or being carless with its power can also overwhelm a person and turn them into TheHeartless.
** In ''VideoGame/KingdomHeartsII'', utilizing your Drive Form repeatedly may result in Sora turning into his Anti-Form that resembles a feral Heartless. Although the form can fight with near limitless combos with darkness based attacks means it can never be used to defeat a boss and the inability to control its appearance, lack of healing and fragility make it, for the most part, [[DeadlyUpgrade a penalty]].
** ''VideoGame/KingdomHeartsIII'' shows this corruption in full force [[spoiler:when Ansem, Seeker of Darkness, uses a darkness attack against Aqua when she tries to protect Ansem the Wise from being kidnapped by him. Due to Aqua being without her Keyblade or any sort of protection from the Realm of Darkness' effects, Ansem's attack is able to finally corrupt her heart, so when Riku and King Mickey find her later, her corruption has taken full effect, with her blue eyes and hair now having taken on appearances similar to Xehanort, her clothes becoming tattered and shredded, and her voice dripping with hatred and malice]]. [[spoiler:Sora has to literally BeatTheCurseOutOfHim to purge Aqua of her corruption and return her to normal]].
* In the ''VideoGame/KnightsOfTheOldRepublic'' series, DarkSide Corruption is more overtly and supernaturally corrupting than in the films, making people who draw on it too heavily appear pale and gaunt with black veins running across their skin. In ''VideoGame/KnightsOfTheOldRepublicIITheSithLords'', your EvilMentor Kreia/Darth Traya is only around 50 but [[YoungerThanTheyLook looks to be in her 70s]] because of it and she's a ''mild'' case. Darth Sion, on the other hand, is essentially a walking corpse.
* ''VideoGame/TheLegendOfZeldaBreathOfTheWild'' has "Malice", Ganon's malevolence, which takes the form of a a black-and-purple slime-like substance that is left behind by [[EldritchAbomination Calamity Ganon]]'s influence. The [[HumongousMecha Divine Beasts]] built to fight him have Malice inside, causing them to turn on Hyrule, along with the [[MechaMooks Guardians]], the automated {{Magitek}} soldiers created by the Sheikah to aid in Hyrule's defense. The grounds around Hyrule Castle, where Ganon is contained, are infested with Malice as well. The ancient dragon Naydra is first found covered in Malice, which Link needs to destroy to free it.
* The Taint of ''VideoGame/{{Lusternia}}'' is the effluence of an EldritchAbomination. Those subjected to it lose their moral compunctions and become stronger, more intelligent, taller, and [[EvilMakeover more demonic-looking]]; prolonged exposure exaggerates these characteristics further and can result in [[TheUndead lichdom]]; and overdosing results in ''serious'' BodyHorror. [[BlobMonster Gorgulu]] - the former ruler of Shallamar - is a good example of the latter.
* ''VideoGame/MajinAndTheForsakenKingdom'' had The Darkness, which turns people into living tar monsters that can't be killed permanently. It also appears to warp their personalities in such a way that they serve the darkness without losing a twisted form of their own personality. Tepeu grows a tar coating from his feet up as he takes damage, though the majin can cleanse him any time they're not in combat.
* Negative share energy is a major plot point of ''VideoGame/MegadimensionNeptuniaVII''. It converts good feelings into pure hatred, driving them insane with hate. [[spoiler: Kurome is corrupted by it to the point that it's her main power source rather than share energy, and she manipulates things behind the scenes in the ''Hyperdimension G'' arc by using it to drive other insane, including the Gold Third, Affimojas and Warechu. Later, in the ''Heartdimension H'' arc, Kurome kidnaps the [=CPUs=] and [[MindRape Mind Rapes]] them using negative energy to power the Dark [=CPUs=] and turn them against the rest of the heroes.]]
* Using Dark Chips in ''VideoGame/MegaManBattleNetwork 4'' and ''VideoGame/MegaManBattleNetwork 5'' will permanently reduce Megaman's maximum HP by 1 for each use. Eventually after prolonged usage of Dark Chips, it results in irreversible corruption but can allow the player to use Dark Navi Chips.
** The [[VideoGame/MegaManStarForce sequel series]] has "Noise". Noise, unlike other examples of this trope, isn't actively ''evil'' or even intelligent, just so chaotic that it seriously screws up any other EM waves (as well as biological systems) in high concentrations.
** ''VideoGame/MegaManZX'', courtesy of another scientifically-based (of sorts, just like the other examples above) ArtifactOfDoom, the original Biometal Model W. Model O seems to be this as well.
** ''VideoGame/MegaManBattleNetwork 6'', where you can use your Beast Form (wolf or hawk depending on game) for three turns before it ends and you go into a weakened state. The trope comes into affect both in battle, where you lose control of Megaman if you enter Beast Mode again, and in the story, where Megaman several times nearly loses control to the beast.
** Does ''Megaman X'' series ring a bell? Zero is practically a walking virus magnet.
* The ''VideoGame/MetroidPrimeTrilogy'' features this as a very prominent theme, concerning a highly toxic blue substance known as Phazon capable of corrupting everything, from small animals to entire planets. Throughout the games, Phazon takes over animals, Metroids, highly advanced alien races, ghosts, machines, and entire planets, and takes sentient forms. The Chozo even refer to it as The Corruption.
** ''VideoGame/MetroidPrime'' is set in the once paradisial planet Tallon IV, which was hit by a Phazon bearing meteorite known as a Leviathan around twenty years prior to the game. The resident naturalist Chozo tribe had to leave when the planet began falling apart due to Phazon corruption. The primary ''Metroid'' antagonists, the SpacePirates, discover the mutagenic properties of Phazon and begin experimenting with it to [[GeneticEngineeringIsTheNewNuke improve their forces]]. Throughout the story, the player comes across several creatures infected by Phazon, most notably Elite Pirates, Fission Metroids, and Metroid Prime itself.
** In ''VideoGame/MetroidPrime2Echoes'', Samus visits a second Leviathan-struck planet. Planet Aether became unstable due to the interaction between its own physical properties and those of Phazon, resulting in a permanent state of trans-dimensional flux that connected it with another version of itself, dubbed Dark Aether. Dark Aether is a barren wasteland full of Phazon, albeit not inhospitable, being inhabited by the Ing, which also have parasitic and corrupting abilities. The Ing attacked the Luminoth, native to Light Aether, as well as Space Pirates who arrive to harvest the Phazon, and the entire planet broke into a war of three opposing sides for survival. Several Aether creatures and those brought from Tallon IV by the pirates become victims of both Phazon and Ing corruption as well. Only one Ing (the FinalBoss) is willing to touch Phazon without a middleman. That should have warned people.
** ''VideoGame/MetroidPrime3Corruption'' opens with attacks on three planets by Leviathans. Bryyo and Elysia are impacted by the meteorites, while Norion is saved in the last moment by Samus and the other hunters. In the process, all four hunters become infected with Phazon, and their bodies develop a tumor-like Phazon-producing gland that slowly corrupts them. The Galactic Federation decides to take advantage of the hunters' corruption by adapting their body suits with a "Phazon Enhancement Device" weapons system. ''[=MP3=]'' partially averts the mook rule, as GF troopers can safely use phazon via tanks,[[note]]For the most part, anyway. While on the Valhalla, you can scan a dead P.E.D. Trooper whose suit malfunctioned. The results are quite disturbing.[[/note]] while Samus is under serious threat of [[NonstandardGameOver Terminal Corruption]] whenever she uses her P.E.D. for extended periods. Her fellow hunters all fall victim to it. Samus is later sent to investigate the other attacked planets as well as [[spoiler:the corrupted Space Pirate Homeworld and Phaaze, a seemingly [[GeniusLoci sentient planet]] entirely made of Phazon.]] With each main boss Samus beats, the resulting blast of Phazon energy further infects her, visualized by the tumor growing in her stomach. There are [[BodyHorror growing deformities on her face]], which can be seen reflecting in her visor, as well. By the end, one eye is completely black, the other is bright "Phazon blue," and there is a [[TaintedVeins Phazon vein]] down the middle of her face. [[spoiler:On Phaaze, her corruption grows so great that ''her ship stops recognizing her,'' and she's forced to continually vent energy however she can to prevent the corruption from consuming her.]] If at any point she becomes fully corrupted, the game ends [[spoiler:and she becomes a new Dark Samus]].
* ''VideoGame/MonsterHunter'':
** ''VideoGame/MonsterHunter4'' introduces the Frenzy, a virus spread by the enigmatic Gore Magala that eventually drives monsters infected by it crazy, giving them a sickly purple hue, GlowingEyesOfDoom, and increased speed and strength. While most of them end up dying not long after, some of them manage to overcome its negative effects, transforming into an even deadlier state known as Apex. The player themselves also can catch the virus from an infected monster, which results in them eventually being either weakened or strengthened depending on whether or not they're able to overcome it by exerting themselves in combat enough before it can run its course. The mental health issues and risk of death are apparently exclusive to monsters.
* ''VideoGame/MonsterHunterWorld'': The noxious effluvium of the Rotten Vale can infect small monsters and drives even the normally passive raphinos into blind aggression. The Black Veil Vaal Hazaak spreads spores that generate effluvium wherever it wanders, spreading the infection to other regions.
* The Spirit Eater affliction in ''VideoGame/NeverwinterNights2: Mask of the Betrayer''. The game's storyline branches depending on how you resist it/use it leading to multiple endings. In the best [[spoiler:you're cured]], in the worst [[spoiler:you become a god-killing abomination]] and {{Bittersweet Ending}}s are also available.
* ''VideoGame/ObsCure'':
** The games have the mortifilia plant, a bizarre, photophobic plant that turns people exposed to it into monsters with powers over darkness, albeit with a fatal weakness in the form of being [[WeakenedByTheLight highly vulnerable to light]] (direct sunlight and flashbang grenades will kill them almost instantly, but even an old flashlight will weaken them). It was discovered around the turn of the 20th century in DarkestAfrica by the Friedman brothers, a pair of {{Adventurer Archaeologist}}s searching for the key to {{immortality}}. Herbert Friedman and his wife did become immortal, but his brother Leonard was mutated into a giant plant monster, causing Herbert to devote his life to researching the plant to find a cure. He established a high school to fund and cover up his experiments and provide a ready pool of [[PlayingWithSyringes test subjects to work on]], many of whom also turned into monsters who eventually break out.
** In the sequel, with Friedman defeated, the mortifilia plant starts spreading like wildfire over the ruined high school and beyond, eventually becoming a popular drug at a nearby university once the students discover its [[MushroomSamba hallucinogenic properties]]. Before long, a second outbreak of darkness monsters erupts on campus. One character from the first game, Shannon, is also seen to have developed a symbiotic relationship with the corruption since then, capable of inhaling and harmlessly neutralizing the spores that the plant releases. Her fellow survivors weren't so lucky, though, and have to constantly take medication in order to suppress the infection. [[spoiler:One of them, her brother Kenny, undergoes a FaceMonsterTurn after [[NoMedicationForMe snapping and refusing to take his meds]].]]
* ''VideoGame/{{Okami}}'' plays this trope a bit more unconventionally, in that the corrupting force doesn't affect an individual person, but rather an environment; a dark red mist spawned by Orochi [[spoiler:as well as Ninetails, Lechku & Nechku, and ultimately Yami]] turns whole portions of Nippon into desolate brownish-gray landscapes where demons are allowed to run amok. These affected areas tend to feature Cursed Zones, which are so saturated in red mist that they physically harm Amaterasu, drowning her if she stays in them for too long. At one point, Ammy finds Kusa Village completely enveloped by a Cursed Zone, but because it's stretched out over a much larger area than normal, the worst it does is drain her ink without letting her recover it until she leaves or purifies the area. Additionally, during the battle against Orochi, his shadow-element head attacks by spitting out purple buds that spray out clouds of red mist, temporarily turning the battlefield into a mild Cursed Zone on-par with Kusa Village. [[spoiler:He does it again during the battles with True Orochi 100 years in the past and on the Ark of Yamato.]]
* ''VideoGame/OriAndTheWillOfTheWisps'' has the Decay, which began overtaking Niwen following the death of the [[FisherKing Spirit Willow]] and the dissolution of its light. Its effects include:
** The most heavily stricken regions, such as the Silent Woods, are bereft of nearly all living flora and fauna, and cause any lingering visitors to be TakenForGranite.
** The water in most areas has turned stagnant and poisonous due to the shutdown of the Wellspring by a MuckMonster.
** The mountainous area known as Baur's Reach suffers from an EndlessWinter, putting its titular guardian in perpetual hibernation.
** The Mouldwood Depths are cloaked in [[DarknessEqualsDeath a darkness that consumes unwitting visitors]].
** The BigBad, Shriek, was orphaned and [[EvilMakesYouUgly hideously mutated]] by the Decay from birth, leading to her being [[AllOfTheOtherReindeer ostracized]] and becoming a ''tatarigami'' as an adult.
** The FinalDungeon, [[TreeTrunkTour set in the roots and trunk of the deceased Willow]], is surrounded by FogOfDoom as well as perpetual lightning storms, is covered in [[TheHedgeOfThorns highly damaging thorns]], and oozes with pink lava-like liquid that is a OneHitKill on contact.
* In ''VideoGame/PandorasTower'', your character's LoveInterest is infected with a curse that slowly turns her into a monster. It can be reversed by feeding her monster meat; the fresher the better, from dried out and rotten (worst) to ''still moving'' (best). The entire point of the game is to collect enough to fully cure her.
* Shadow Pokemon from ''VideoGame/PokemonColosseum'' have their "hearts closed", turning them into vicious, remorseless fighting machines. They get access to unique moves; Shadow Rush in Colosseum, and a variety of Shadow moves in the sequel, ''[[VideoGame/PokemonXDGaleOfDarkness Pokémon XD]]''. In the latter, Shadow moves are [[InfinityPlusOneElement super-effective against all non-Shadow Pokémon]]. However, they will sometimes go into a berserk state where they will attack their allies and even their ''Trainer'' indiscriminately. In both games, a major goal is to "snag" these Shadow Pokémon and purify them, freeing them of their corruption through ThePowerOfFriendship.
* [[spoiler:[=GLaDOS=]' chassis]] in'' VideoGame/Portal2'' seems to cause any AI who is installed into it to become a [[ScienceRelatedMemeticDisorder testing-obsessed]] [[AxCrazy maniac]]. [[EnemyMine GLaDOS]] is notably nicer and saner after being removed from it[[note]]although this might simply be her ''acting'' nice because she needs Chell[[/note]], while Wheatley [[spoiler:[[FaceHeelTurn turns on Chell]] and starts trying to kill her after being placed in it. After [=GLaDOS=] is placed back in, she instantly goes back to being crazy and spares Chell only because she thinks killing her isn't worth the effort]].
* ''VideoGame/PrinceOfPersia2008'': Ahriman's essence - a black tar-like substance ''called'' corruption - is a bit of a subversion. While it drains the land of life around it, it also only afflicts people who [[DealWithTheDevil made a pact with Ahriman]]. So really, if you become a Corrupted, it's your own fault.
** Making a DealWithTheDevil makes you into a more Badass corrupted and lets you keep some of your original personality. Just getting conquered by Ahriman or falling into the corruption turns you into a Mook version. Elika also mentions that some people who made deals just got turned into the mindless soldier version anyway.
*** The Sands of Time from the last-gen ''VideoGame/PrinceOfPersia'' corrupt people in a very similar fashion, and are responsible for the prince's SuperpoweredEvilSide in the Two Thrones.
* The Void in ''VideoGame/ProjectSpark'' is a malevolent force that twists and warps everything it touches into a sinister version of itself.
* The ''Franchise/ResidentEvil'' series gives many examples:
** The [[NightmareFuel infamous]] Keeper's Diary found in ''VideoGame/ResidentEvil'' chronicles the resident animal handler who is infected with the T-Virus and doesn't realize it. He goes from normal to itchy to rotting and insane, ''and still writing'':
-->'''May 21 1998:''' Itchy itchy Scott came ugly face so killed him. Tasty. 4 / / Itchy. Tasty.
** The G-Virus in ''VideoGame/ResidentEvil2'' works like this as seen in William Birkin, who starts out as a man with an overgrown arm and claws but ends up as an [[BlobMonster amorphous mass]] of teeth, claws, tentacles, [[EyesDoNotBelongThere and eyes]]. A similar fate would have befallen his daughter who he infected, but she is given a cure and walks away unmutated but with an absurdly powerful HealingFactor.
** The Las Plagas works like this, infecting a host and slowly assuming control. Both Leon and Ashley end up infected and have to keep pounding medication until they find a cure, while the [[OurZombiesAreDifferent villagers weren't as lucky]]...
** Uroboros typically acts too quickly to count as it devours its host in seconds, but [[spoiler:Albert Wesker ''already'' being hopped up on a different super-virus was able to handle it long enough (albeit slowly losing himself) for one last-ditch attempt to kill Chris and Sheva]].
** The T-Abyss virus works this way, with some of its victims being corrupted so badly that they don't even realize that they've been mutated. The Comms Officer, now a horrific monster called a Scagdead, continued to radio for help and pleads "Please stop, I'm human" as it tries to kill you.
* The Chimera in ''VideoGame/{{Resistance}}: Fall of Man'' utilize TheVirus to transform humans into aliens and fight for your side. The protagonist of the game is also infected, but although he is mutated, he manages to retain his personality.
** ''Resistance 2'' reveals that he is not unique, but that all members of the special squad he's assigned to must regularly use suppressors to prevent them from becoming Chimera. These suppressors have side-effects, such as [[WithGreatPowerComesGreatInsanity prolonged periods of psychosis.]]
* The Dark Glass from ''VideoGame/RiseOfLegends''. It made the Dark Alin, which terrorized the Alin kingdom. In-game Dark Glass units have an attack which gives a permanent HP debuff.
* ''VideoGame/{{Ryzom}}'' features a substance called the Goo, which is purple [[ExactlyWhatItSaysOnTheTin goo]] that spouts from fissures in the ground; the Goohead tribe abuse it as a psychedelic drug, the local wildlife becomes stronger and more hostile around it, and too high of a concentration of the stuff will cause you continuous damage while you're in the area.
* ''VideoGame/TheSecretWorld'' has the Filth, extradimensional black goo that seeps into this reality and does various horrible things to those who come in contact with it. Fortunately, the player character is immune thanks to the Bee inside them.
* ''VideoGame/ShadowMan'' has the Dark Souls, which can be implanted in living individuals to grant them magical powers and immortality (as long as the Soul isn't removed), but at the cost of turning them into cruel serial killers - or, in the case of the Five, even ''more'' cruel serial killers. Mike, being the titular Shadow Man and possessing powers related to the dead and souls, can absorb them and suppress their evil completely at the cost of also suppressing most of their powers: this translates into a little power-up for each Soul absorbed, with no drawbacks. On the other hand, trying to harvest the full power of many Dark Souls is [[PhlebotinumOverload a bad idea]].
* Done beautifully in ''VideoGame/ShadowOfTheColossus''. After every time you defeat a colossus, some weird dark tendrils come out and latch into The Wanderer. [[spoiler: The effect is gradual enough that you don't notice how bad it's gotten until the final colossus, where (because of the wind and some camera close ups) you finally see how ragged and bad he looks, compared to the young man you started the game as.]]
* ''VideoGame/SoulSeries'' has Malfestation, a condition caused by the [[EvilWeapon Soul Edge]]'s energy that can transform both humans and animals into monsters. The transformation can very from individual to individual: some may just be driven into a maddened, berserker state, others are altered into outright inhuman forms - Raphael becomes a [[OurVampiresAreDifferent vampire-like being]], while Cervantes is turned into a {{ghost pirate}} - and there are those that appear to not have changed at all such as [[TheBaroness Isabella "Ivy" Valentine]], who was born from Cervantes while influenced by Soul Edge and her most notable traits are [[TheAgeless immortality]] and having MysticalWhiteHair and due to her cursed lineage, she [[[CelibateHero refuses to have children]] and pass it to someone else. This condition can be cured depending on the circumstances, as seen with [[TheHero Siegfried]] being taken over by the Soul Edge and turned into [[EnemyWithin Nightmare]], but he was able to break free from its control. Kilik and the Edge Master also known a purification art that can cure Malfested.
* In ''VideoGame/SpaceQuestVTheNextMutation'', a failed experiment in [[GeneticEngineeringIsTheNewNuke genetic engineering]] creates the Puckoid plague that takes over at least one colony and the Confederation's flagship. It causes the infected beings to melt into primordial goo.
* ''VideoGame/SpiritsOfAnglerwoodForest'': [[spoiler: Ezra]] is the victim of this. As a child, he is lured deep into the forest and [[spoiler: his spirit is captured and corrupted by something, possibly the forest itself. He becomes obsessed with luring his family into the forest along with him and eventually sets his sights on [[TheHero Edgar]]]].
* In ''VideoGame/{{Submerged}}'', as you progress you are observed by the city's aquatic inhabitants. Your skin slowly starts turning grey and green and it quickly becomes obvious that you're transforming into one of them.
* The Pox of [=LeChuck=] in ''VideoGame/TalesOfMonkeyIsland''. Whoever gets infected with this voodoo plague slowly loses their ability to reason and becomes more and more violent. It only seems to affect pirates for some reason, though.
* ''VideoGame/{{Terraria}}'' has this in spades with the biome [[ExactlyWhatItSaysOnTheTin of the same name]]. It also has a much more sinister, BloodierAndGorier version of ''that'' with its Crimson. They both can spread over grass, but can easily be stopped with various barriers... Until you activate Hardmode by beating the Wall of Flesh. After activating Hardmode in a world they can corrupt almost any natural terrain, and a massive V shape is corrupted from the bottom of your world to the top, half the Corruption or Crimson, and half the newly unleashed Hallow, a SugarBowl corruption that's [[LightIsNotGood actually just as dangerous]] and will happily turn your world [[CrapsaccharineWorld crapsaccharine]] if you let it. Good luck with that...
* Ever since acquiring the [[TomeOfEldritchLore Book of Claws]], the protagonist of ''VideoGame/TheyBleedPixels'' has acquired a monstrous form that she transforms into every night. But every time she transforms and fights the monsters of the dream world, the line between her humanity and the monstrous form of her dreams gets thinner and thinner. [[spoiler:The Headmaster is encouraging this of his students in order to get himself a supply of monstrous servants. And the Book of Claws is not the only tome of its kind in the school's library]].
* Ember in ''VideoGame/{{Torchlight}}'' has this effect, granting magical power but at the risk of turning you evil.
** Double-subversion; the ember itself wasn't corrupting, but the source of the Ember Blight was Ordrak, whose Heart continued to corrupt after his death. The Alchemist becomes obsessed with magical experiments on the Heart and Blighted Ember, succumbs to the corruption after donning armor made of it, and destroys Torchlight at the start of ''VideoGame/TorchlightII''.
* The first villain faced in ''[[VideoGame/TronTwoPointOh Tron 2.0]]'' is an former executive who was incorrectly digitized into the computer world and became a virus, his poisoning presence was even referred to as The Corruption. Infected programs who attack you have a chance of infecting one of your subroutines (weapons and equipment), making it have the opposite effect until you complete a virus scan on that subroutine. Oddly, you eventually get to use the special weapons of the Corrupted yourself without risk of self-infection.
* In ''VideoGame/TwistedWonderland'', Magic use generates a harmful by-product known as 'blot', similar to black ink in appearance. Blot accumulates in the caster's body and naturally dissipates with sufficient rest and minimal further magic use, but builds up more quickly with stress and negative emotion. Students have pens with magic crystals which siphon off blot and prevent it from building up in their bodies directly; use of magic causes blot to accumulate in the crystal instead. When the crystal is filled with blot beyond its capacity (or when the caster is overwhelmed by negative emotion, inevitably resulting in the same outcome), [[spoiler:the caster enters an AxCrazy state known as Overblot, taking on a [[EvilMakesYouMonstrous corrupted, more monstrous form]]. The only way to save an Overblot victim is to wear them out before they burn through their excess magic, lest they fully become monsters like the one in Dwarf Mine.]]
* The Filth in ''VideoGame/{{Unworthy}}'' is an archetypal example. It is literally the solid form of sin, and so there's no surprise it amplifies the humans' worst traits. Many were simply rendered hostile without getting anything special in return, but the bosses like Gaston, Heir of Ambition, and Kayen, Father of Thirst received genuine superpowers as a result.
* ''VideoGame/{{Warcraft}}'' universe:
** Demons seem to radiate fel energy and any area with large amounts of demons will become either a barren wasteland or a twisted mockery of its former self. Living beings exposed to fel energy will mutate, making them more powerful but turning them insane, and causing them to become demons after long enough exposure. In fact, most demons were mortals before they were corrupted by fel energy.
** Also seen with the influence of the [[EldritchAbomination Old Gods]] on mortals. Their Curse of Flesh transformed the immortal stone creations of the Titans and into mortal flesh and blood beings who were more susceptible to their whispers.
** Turned into an actual game mechanic in ''VideoGame/WorldOfWarcraft'' with [=Cho'gall=]. He inflicts his enemies with "Corrupted Blood" which gradually twists and mutilates their body, causing them to eventually sprout hostile tentacles before [[BodyHorror transforming into a Faceless One]].
** The Sha from ''Mists of Pandaria'' are an EmotionEater version of this. They are empowered by negative emotions such as fear, despair, and anger, and can corrupt and control sentient creatures as well as the environment.
** The Nightmare is a corrupting force within the Emerald Dream that twists any being connected to it, such as druids and dryads, into hateful monsters. It finally comes to a head in ''Legion'' when Xavius uses the Nightmare to corrupt [[spoiler:Ysera and Cenarius]].
** The Old Gods themselves a form of corruption meant to infest planets and corrupt the world spirits which can one day grow into [[spoiler:Titans]]. It was after seeing what this sort of corruption can create that Sargeras decided it was better to ''destroy'' every world spirit instead.
** Void energy is corrupting, both physically and mentally. If the user cannot resist, they are driven insane by the whispers of the Void Lords and are twisted into pale, pathetic creatures consumed by hunger.
** The blood of the dead god Sethe only effects the Arakkoa of Draenor. Any Arakkoa who is cast into the blood is warped into a hunched, misformed mockery of their natural body. They also lose their natural affinity for Light magic, but in turn gain an innate mastery of Shadow magic.
* ''VideoGame/TotalWarWarhammer'' and [[VideoGame/TotalWarWarhammerII its sequel]] have multiple forms of corruption:
** The first and most obvious is Chaos, spread by its legions and a smattering of other Chaos-aligned subfactions (such as [[TheHedonist Morathi's]] Slaanesh-worshipping Cult of Pleasure). It causes Public order and economy penalties for most factions, but bonuses to leadership and war spoils for Chaos factions.
** Vampiric corruption is spread by the Vampire Counts and pirates of the Vampire Coast. It causes attrition to living armies moving through it, but moving through areas without it causes undead armies to decay the same way.
** Skaven corruption is spread by, well, [[ExactlyWhatItSaysOnTheTin Skaven]]. It causes public order and income penalties as the subterranean menace creeps in and steadily overpopulates an area. Uniquely, Skaven themselves suffer the exact same penalties (arguably even harsher than others, since it also affects their unique food resource) and have means to both spread and clear their own corruption, leading to a constant battle with themselves. Well, they are [[ChronicBackstabbingDisorder Skaven.]]
** Untainted, the "pure" state, actually counts as well. It can be "spread" by non-corrupting factions just as corruptive ones spread theirs, and wielded to inflict penalties the same way. Most factions don't get any benefit besides lacking the penalties and denying corruptive enemies a foothold, save for a few special cases (i.e. Alarielle suffers special penalties as Chaos spreads).
* Whereas in the [[VideoGame/MortalKombatDeception original course]] of events in ''Franchise/MortalKombat'' Raiden became DarkerAndEdgier because he reconstituted wrong, in the new timeline Raiden's actions in ''VideoGame/MortalKombatX'' cause him to absorb the negative energy that was pumped into the Jinsei (Earth's life force) by Shinnok. While he saved Earth and the Jinsei from Shinnok's influence, he himself succumbed to it and has become much like his hardline counterpart in the original timeline.
* ''VideoGame/{{Warframe}}'': While the "corrupted" faction are more like techno-zombies cybernetically reanimated by the [[SufficientlyAdvancedTechnology ridiculously high-tech]] Orokin towers, the Void does work like this. Those exposed to it gain strange powers but also go violently insane ([[DemonicPossession or possibly are possessed by an eldritch entity from beyond time and space]]; it's unclear). Furthermore, since all existing Orokin towers are in the Void, the Corrupted faction are often heavily afflicted by the Void. The only ones known to use Void powers safely are the Tenno. [[spoiler:They were created when their colony ship, the ''Zariman 10-0'', was lost in the Void. The adults all went insane, but the children became nigh-immortal liminal beings with strange powers. When they were finally rescued, the Orokin crafted the warframes to channel their Void powers and fight the Sentients.]]
[[/folder]]

* ''VisualNovel/HigurashiWhenTheyCry'' plays around the cause and effect [[spoiler:Hinamizawa Syndrome is just a parasite that attacks the frontal lobe, so the afflicted becomes a very angry schizophrenic, with super strength [[PowerBornOfMadness Born Of Madness]]. It also makes them hear the desperate pleas of the local deity but that's hardly a power up at all]].

* In ''VideoGame/SpaceQuest'' 5, a failed experiment in [[GeneticEngineeringIsTheNewNuke genetic engineering]] creates the Puckoid plague that takes over at least one colony and the Confederation's flagship. It causes the infected beings to melt into primordial goo.

* In ''WesternAnimation/AdventureTime'', the [[ArtifactOfDoom Ice Crown]] grants its wearer [[AnIcePerson ice powers]] and an incredible HealingFactor; however, it ''also'' [[spoiler: [[BodyHorror physically]] and [[WithGreatPowerComesGreatInsanity mentally]] warps them. The process completely destroys the person's identity, and can take ''years'' if they have sufficient willpower (but it's ultimately irresistible and uncurable). Oh, and the person [[AndIMustScream is fully aware of it the entire time.]]]] The worst part is that the Crown is an ImmortalityInducer, and NoImmortalInertia is in full effect. So even if the wearer is freed, he/she will die soon as the time deferred by the Crown catches up to him/her.

* ''Series/{{Willow}}'': Commander Ballantine is wounded by one of the Gales during their attack, and this is shown to infect him. He turns into a servant of the Crone, then infects other guards in his party to be the same.

* Fel (demonic energy) has this effect in ''VideoGame/{{Warcraft}}'' universe. Demons seem to radiate fel energy and any area with large amounts of demons will become either a barren wasteland or a twisted mockery of its former self. Living beings exposed to fel energy will mutate, making them more powerful but turning them insane, and causing them to become demons after long enough exposure. In fact, most demons were mortals before they were corrupted by fel energy.

* ''[[VideoGame/MonsterHunter Monster Hunter 4]]'' introduces the Frenzy, a virus spread by the enigmatic Gore Magala that eventually drives monsters infected by it crazy, giving them a sickly purple hue, GlowingEyesOfDoom, and increased speed and strength. While most of them end up dying not long after, some of them manage to overcome its negative effects, transforming into an even deadlier state known as Apex. The player themselves also can catch the virus from an infected monster, which results in them eventually being either weakened or strengthened depending on whether or not they're able to overcome it by exerting themselves in combat enough before it can run its course. The mental health issues and risk of death are apparently exclusive to monsters.
* In ''VideoGame/MonsterHunterWorld'' the noxious effluvium of the Rotten Vale can infect small monsters and drives even the normally passive raphinos into blind aggression. The Black Veil Vaal Hazaak spreads spores that generate effluvium wherever it wanders, spreading the infection to other regions.

* The ''VideoGame/ObsCure'' games have the mortifilia plant, a bizarre, photophobic plant that turns people exposed to it into monsters with powers over darkness, albeit with a fatal weakness in the form of being [[WeakenedByTheLight highly vulnerable to light]] (direct sunlight and flashbang grenades will kill them almost instantly, but even an old flashlight will weaken them). It was discovered around the turn of the 20th century in DarkestAfrica by the Friedman brothers, a pair of {{Adventurer Archaeologist}}s searching for the key to {{immortality}}. Herbert Friedman and his wife did become immortal, but his brother Leonard was mutated into a giant plant monster, causing Herbert to devote his life to researching the plant to find a cure. He established a high school to fund and cover up his experiments and provide a ready pool of [[PlayingWithSyringes test subjects to work on]], many of whom also turned into monsters who eventually break out.

* In ''VideoGame/DarkEarth'', your character Arkhan is poisoned by a face full of liquid evil while on his very first day on his new job as a Guardian of the Flame, and starts to mutate into a creature of the Dark. You must help him find a cure before the transformation is complete. While one side-effect of the mutation is a [[TookALevelOfBadass Level of Badass]], the more you use it, the more the mutation takes hold. When the mutation reaches 100%, you get a [[NonStandardGameOver Non-standard Game Over]].

** There's also Red Lyrium, a variant of [[GreenRocks Lyrium]] that can infect people and turn them into horrific monstrosities, with similar effects on their sanity. [[spoiler:It is revealed in ''VideoGame/DragonAgeInquisition'' that Red Lyrium is actually Lyrium that has been infected by the Blight.]]

[[caption-width-right:300:The itsy-bitsy Klyntar crawled up the spider's arm...]]

* Dark Energon in ''WesternAnimation/TransformersPrime'' is more or less the Transformer equivalent of Satan's blood. Anything it touches becomes motile and malevolent, including dead bodies. Living 'bots that take it in tend to get powerups, but also go insane as they bend slowly to Unicron's will[[note]] Megatron, the primary infected so far, seems to be doing pretty well as far as independence goes so far, but he also seems to act like the dark energon is telling him what to do at times[[/note]].
** Also makes an appearance in ''VideoGame/TransformersWarForCybertron'', a videogame to which ''WesternAnimation/TransformersPrime'' is [[BroadStrokes sorta]] a sequel. It's less corrupting there for living or formerly living things, but a lot more corrupting for nonliving things and feral creatures.
*** The novel ''Transformers: Exodus'', which is sort of a prequel and adaptation of the game, is very explicit about the corruptive influence of Dark Energon. Start with euphoria, boosted power, and greatly increased violent tendencies... then add on instant addiction that will kill you real slow if you try to kick the habit. Oh, and the stuff turns any normal Energon it comes in contact with into more Dark Energon.
** In ''Predacons Rising'', the Dark Energon [[spoiler:prevents Megatron from [[BarredFromTheAfterlife joining the All-Spark after death]] and allows Unicron to hijack and transform his body.]]

In the standard plotline, it will usually infect TheHero at some point. While [[VampireRefugee seeking to cure himself]], the infected hero must [[ThisIsYourBrainOnEvil struggle with malign influence]] and limit use of the [[SuperpoweredEvilSide evil powers]] granted by the Corruption, since using them tends to corrupt him further.

* In the {{Roguelike}} ''[[VideoGame/AncientDomainsOfMystery ADOM]]'', the BigBad are the forces of Chaos, very similar to ''TabletopGame/{{Warhammer}}'' and ''TabletopGame/Warhammer40000'', including the corruption. There are several sources of corruption, including background chaos radiation which grows stronger as you approach the source ([[spoiler:The Chaos Gate]]). Corrupted monsters may turn into writhing masses of primal chaos. A corrupted player will gain additional powers and be a writhing mass of BodyHorror. Corruption-removal methods are the most sought-after thing in the whole game, because getting the full set of corruptions means you're close to an unavoidable NonStandardGameOver. And because some of the corruption side effects are really, really bad for your character. For instance, you can be drastically slowed down, instantly drain every magic wand you touch, poison everything you handle (including your own food and potions), and worst of all is the "unholy aura" one; everyone you meet, including powerful [=NPCs=], will become hostile at the mere sight of you.\\
\\
However, some corruptions [[CursedWithAwesome grant you useful powers]], and for several of the special endings, you need to be corrupted almost to the point of dissolution.

** The Brood Mothers take this a step further: [[spoiler: Human, elf, dwarf and qunari women are captured by the Darkspawn and force-fed Darkspawn blood. In order to survive they have to give in to the urge to eat the others which drives them mad and turns them into Brood Mothers]]

** It got worse in the ''VideoGame/DragonAgeII'' {{DLC}} "Legacy" with TheReveal that [[spoiler:Wardens don't die, but simply turn into ghouls when they hear the Calling. There is no avoiding ghoul-dom once the Taint enters a person's body and the Warden's unique version of the Taint simply delays the effects from becoming apparent by a few decades, hence why the Senior Wardens prefer to go out in a blaze of glory against the Horde before this happens. Larius, a former Commander of the Grey, was unlucky enough to survive long enough to turn and is now basically ''ignored'' by the Darkspawn.]]

* In the first few ''[[VideoGame/DotHackR1Games .hack//]]'' games, the ones where Kite was the protagonist, Kite has an ability called Data Drain (which causes the enemy to be weakened to a point where they are pretty easily killable) but using it causes Kite to risk infection from a computer virus, the very same virus that created Data Drain no less. If the infection reaches 100% then it's game over (the Data Drain is necessary to kill certain bosses in the main quest, but no infection is received from those bosses. It's also required to get "cores" which unlock story levels). In fact, as the % goes up, there's always a slight (increasing) chance of getting a game over. Not using it reduces the number.
* In ''VideoGame/{{Iconoclasts}}'', clumps of strange blue eyes appear soon after leaving The Tower. They are harmless...until they sense a sufficiently weakened target, and latch on to it to control it. The first such encounter is with Possessed Thunk, where a clump of these had colonized One Concern's Kerthunk mech, and [[spoiler: controlled the Silver Watchman, with an eye going over his face, and strings connecting it with the rest of the colony.]]
** Afterwards, they [[spoiler: latch onto Agent Black at the end of her fight with Robin and Royal, she was being torn apart by the Isi seeds blooming inside her. Their effects allowed her to be "reborn" as an enormous screaming creature with the body made of Ivory trees, forcing Robin to kill her again...and again, as the "core" of that Ivory Beast separates and desperately tries to scale the rocket for one last time.]]
** Lastly, these blue eyes have taken over all the creatures in the [[spoiler: Star Worm's Impact Zone]], turning them invulnerable to damage until Robin can get them off. Their origin is never explained outright, but it seems that [[spoiler: they are something produced by the bird species Star Worm's pilot belonged to, whether naturally or technologically. They were the means through which both the Omega Controller and the Star Worm itself were commanded, and when the eye was destroyed, the Star Worm ultimately killed the pilot on its own, rather than that being a simple failure of the controls.]]

---> '''Oracle''': I sense there is a dark rage burning within you, and in time, it will destroy you with its madness. Only the last power of the Precursors can save you.

* [[spoiler: [=GLaDOS=]' chassis]] in'' VideoGame/Portal2'' seems to cause any AI who is installed into it to become a [[FantasticDrug testing-obsessed]] [[AxCrazy maniac.]] [[EnemyMine GLaDOS]] is notably nicer and saner after being removed from it[[note]]although this might simply be her ''acting'' nice because she needs Chell[[/note]], while Wheatley [[spoiler: [[FaceHeelTurn turns on Chell]] and starts trying to kill her after being placed in it. After [=GLaDOS=] is placed back in, she instantly goes back to being crazy and spares Chell only because she thinks killing her isn't worth the effort.]]

--> '''May 21 1998:''' Itchy itchy Scott came ugly face so killed him. Tasty. 4 / / Itchy. Tasty.
** The G-Virus in ''VideoGame/ResidentEvil2'' works like this as seen in William Birkin, who starts out as a man with an overgrown arm and claws but ends up as an amorphous mass of teeth, claws, tentacles, [[EyesDoNotBelongThere and eyes.]] A similar fate would have befallen his daughter who he infected, but she is given a cure and walks away unmutated but with an absurdly powerful HealingFactor.
** The Las Plagas works like this, infecting a host and slowly assuming control. Both Leon and Ashley end up infected and have to keep pounding medication until they find a cure, while the [[OurZombiesAreDifferent villagers weren't as lucky...]]
** Uroboros typically acts too quickly to count as it devours its host in seconds, but [[spoiler:Albert Wesker ''already'' being hopped up on a different super-virus was able to handle it long enough (albeit slowly losing himself) for one last-ditch attempt to kill Chris and Sheva.]]
** The T-Abyss virus works this way, with some of its victims being corrupted so badly they don't even realize they've been mutated. The Comms Officer, now a horrific monster called a Scagdead, continued to radio for help and pleads "Please stop I'm human" as it tries to kill you.

** [[ThePowerOfHate Hatred]] is also portrayed as this throught the series, with the CycleOfRevenge being portrayed as a mix between a HatePlague and TheVirus.

* The Technarch Transmode virus in {{Creator/Marvel}}, even in an otherwise benign symbiosis, such as between Warlock and Cypher, and works both ways; as the organic lifeform becomes techno-organic the infector becomes Magus, a more powerful entity hostile toward organic forms and its own offspring.

* The Cure from ''Roleplay/RubyQuest''. When it's first taken by a person, it acts as a panacea, up to and including repairing conditions (such as blindness) present from birth, making it unnecessary for the recipient to eat or drink, and [[spoiler: resurrecting the recipient if they die (though they get amnesia)]]. But once the Metal Glen started using it, everyone taking it began suffering violent fits. It also mutated them whenever they were wounded, eventually turning them into agressive, incoherent masses of BodyHorror. The players met a couple far-gone victims, who they called 'zombies' because of how awful they looked. In its more middling stages, the Cure grants a LovecraftianSuperpower. [[spoiler: Ruby has a cut on her forehead mutate into a ThirdEye, Tom has [[MultiArmedAndDangerous extra arms on his abdomen]], Red has the [[FanNickname Elemental Plane]] [[MoreTeethThanTheOsmondFamily Of Teeth]], and the farther-along Filbert has a mutated arm and a giant gaping maw with teeth stronger than steel. And ''then'' there's Tom Nook.]] Fortunately, the Cure leaves the body quickly, and if one goes enough time without taking it, they will return to normal, [[spoiler: a fact that Red exploited to [[KilledOffForReal kill himself permanently]]]]. Unfortunately, that's harder than it looks, what with [[ImplacableMan Ace]] being the one administering it.

* ''Literature/ParadiseLost'': Gustav Doré's illustrations show Satan's progressive shift from FallenAngel to [[OurDemonsAreDifferent Devil]]. During the flashbacks he appears like a normal angel, albeit with a HornedHairdo. In hell, his wings [[GoodWingsEvilWings molt and become batlike]], and on his way to earth he begins [[EvilCostumeSwitch removing his angelic armor]], [[FullFrontalAssault eventually stripping naked]]. By the end, he's JumpedOffTheSlipperySlope and become the traditional BigRedDevil in mind and body.

* The BigBad of ''Series/UltramanCosmos'' was Chaos Header, a sentient mass of tiny virus-like entities made of light. It primarily menaced Cosmos and EYES by taking over the bodies of peaceful {{kaiju}} to turn them into the MonsterOfTheWeek that they would need to subdue.

* ''Fanfic/AbraxasHrodvitnon'': Members of Alan Jonah's organization who are touched by the decapitated Ghidorah-head's Cthulhu-like influence are either DrivenToSuicide or display signs of this in their SanitySlippage, with Jonah believing himself enlightened as his own type-2 Slippage progresses.

* Just like the [[VideoGame/{{Warcraft}} game it’s based on]], the ''Film/WarCraft2016'' features the fel, a source of magic that greatly increases the powers of whoever is infected by it, but at the price of another being's LifeForce. The corruption aspect is less notable on the orcs, who are already pretty insane without it, but it is what drives [[spoiler: Medivh]] into opening the Dark Portal to Draenor, allowing the Horde to enter Azeroth. It also causes hideous body mutations to the user.

[[caption-width-right:300:The itsy bitsy symbiote crawled up the spider's arm...]]

For when the evil force corrupts a ''location'' instead of a character, see EvilTaintedThePlace.

* In both D6 and D20 versions of ''StarWars'' the RPG, [=PCs=] could acquire Dark Side points by using the Force for aggression or by committing evil acts. In the D6 version, [[NonPlayerCharacter acquiring too many made you lose your character.]] In the D20 version, it [[PoisonMushroom eventually reduced your stats]].