History Main / WithGreatPowerComesGreatInsanity

[[folder:Comic Books]]
!!!Franchise/TheDCU
* ''Franchise/{{Batman}}'':
** An interesting case concerning pre-''ComicBook/{{Flashpoint}}'' ComicBook/{{Azrael}}. When Jean-Paul Valley was born, he was implanted with a brainwashing trance of sorts known as The System, which would grant him amazing strength and agility when he donned the gear of Azrael, though it made him BrainwashedAndCrazy, pushing him to want to kill the guilty. When he first abandoned that role, he functioned pretty well... until the Scarecrow doused him with Fear Gas when JP [[ComicBook/{{Knightfall}} took up the Mantle of the Bat in Bruce Wayne's place]]. The entirety of the subsequent ''Knightquest'' storyline has Jean-Paul constantly fighting The System until he lets Abattoir die. When he does, he finally submits to The System and becomes a fearful mixture of Batman and Azrael and forces Bruce to take back the Mantle.
** Happens to Batman when he gets Superman's power during a battle with the Silver Banshee in a ''ComicBook/SupermanBatman'' story. Batman uses his new powers to bring complete fear and order to Gotham's criminal underworld, and eventually sets his sights on the world, but he becomes increasingly aggressive. With the aid of the Justice League, Superman is able to bring himself and The Dark Knight back to normal. Admittedly this was a BeCarefulWhatYouWishFor ArtifactOfDoom.
* Interesting case with Comicbook/BlackAdam. His powers don't drive him crazy (he went crazy on his own, [[HeelFaceRevolvingDoor and sometimes comes back from that insanity]]...[[AntiHero partially]]), but he can share them, and anyone who would take them on immediately turns evil. ''Anyone'', including [[spoiler:the goddess of love]].
* ''Comicbook/DoomPatrol'': Mento wasn't the most stable/mentally healthy guy to begin with. Then he starts tinkering with a helmet that cranks his PsychicPowers UpToEleven and takes up superheroing. But his wife and her team die, and it REALLY sent him downhill [[FaceHeelTurn until he's doing stints as a supervillain]] and trying to kill his own adopted son! When that heroing team was led by a fellow {{retcon}}ned into a MadScientist and MagnificentBastard, it was damn near inevitable.
* ''ComicBook/{{Firestorm}}'': The curse of the werehyena causes anyone suffering it to gradually go insane. It is theorised that the madness suffered by the werehyenas is one's bestial side taking over, coupled with an exaggeration of negative emotions.
* ''Franchise/TheFlash'': Hunter Zolomon spent his life in a TraumaCongaLine, but he remained a good cop until Gorilla Grodd crippled him and the Flash, whom Hunter considered a friend, refused to use time travel to undo the damage. Hunter attempted to use the Flash's cosmic treadmill himself, but it blew up in his face. The resulting super powers had the side effect of scrambling his thought processes, until he decided that the best way to help his friend the Flash was to make him a better hero through tragedy as Zoom. Hunter still thinks he's helping the Flash, although he gets occasional flashes of MyGodWhatHaveIDone when Wally foils his plans.
* Retconned for Doctor Magnus, the leader of the ''Comicbook/MetalMen''. He needs a careful application of medicine in order to stay stable and good. He's kidnapped along with genuine mad scientists and they cancel his meds, intending for him to regress to his previous level of insane creativity, in which he created a horrific weapon of mass destruction, the Plutonium Man. Though he ''does'' recreate the Plutonium Man, he destabilizes ''very'' quickly, and with the help of several sentient mini-Metal Men he'd managed to cook up in his lab, invents a gun with ''living'' ammo and goes on a rampage (against evil men only), screaming about how he '''''really''''' needed his meds.
* The Psycho-Pirate, a villain with the emotion-changing Medusa Mask, actually had three of them, one for a single emotion, before deciding to combine all three to control all emotions. Unfortunately, continued use ended up driving him insane -- he's first seen in ''ComicBook/CrisisOnInfiniteEarths'' locked away in an insane asylum.
* ''Franchise/{{Superman}}'':
** Arguably [[InvertedTrope completely inverted]] in ''ComicBook/AllStarSuperman'': [[spoiler:Lex Luthor temporarily gains Superman's powers, and while he predictably rampages, he finds himself stopping to examine the amazing perspective his newfound powers and super-senses give him. He eventually concludes that having the level of power and insight that Superman does would make people care for their fellow human beings, and mellows out considerably after losing the powers]].
** One Kryptonite Man is a scientist who thinks Kryptonite ([[KryptoniteIsEverywhere there is now a lot of it on Earth]]) can be used as a safe energy source. When he himself becomes that energy source, he decides to show the world how effective it can be by... a murderous rampage. That never ends well. Later, in the same storyline, another scientist goes cuckoo bananas when he gains control over an oversized amoeba. Or so it seems. Superman subdues the guy, who says he didn't want to do it, but Intergang, a powerful criminal organization, made him.
** Livewire, experiencing some AdaptationalHeroism after [[CanonImmigrant immigrating to the comics]], has her status as a PsychoElectro justified by the observation that, as an {{Energy Being|s}}, taking on more energy affects her equivalent of brain chemistry. In her case more power is literally more insanity. Putting her in Superman's suit from his [[DorkAge blue period]] to regulate her form snaps her to sanity immediately and she soon becomes a hero.
* Matthew Cable from ''ComicBook/SwampThing''. His PsychicPowers and his spiraling alcoholic insanity both stem from the same illicit electroshock treatments.
* ''Franchise/WonderWoman'':
** This is an issue for gods, and the Greek pantheon actually split themselves in two in antiquity to create the Roman pantheon because the influx of worshipers was too much for them. In modern times they don't worry about it as much since they have far fewer worshipers and they've actually rejoined with their Roman counterparts. Some of the gods have trouble with it anyway, like Ares, Aphrodite and Dionysus because their power doesn't just come from worshipers and their attributes influence their mindset and actions.
** ''ComicBook/WonderWoman1987'': Once the White Magician's BlackMagic use starts affecting him physically his mind goes right out the window and he becomes a twisted demonic thing before his death.
** ''ComicBook/WonderWomanOdyssey'': With every unjust death, Nemesis' power grew until she could reign alone above all other Greek dieties, whom all fled to the mortal plan in terror and went into hiding to escape her wrath. It also drove her completely mad.
* In the New 52 arc ''Comicbook/DarkseidWar'', members of the Justice League end up becoming the New Gods after the death of Darkseid and others caused a power vacuum. Batman becomes the New God of Knowledge, taking Metron's chair for his own, and intends to his all-powerful knowledge to bring order to Gotham, even if preventatively. Franchise/{{Superman}} becomes the New God Of Strength when Luthor throws him into a Fire Pit in a deeper attempt to recharge Superman's solar cells. It [[GoneHorriblyRight Goes Horribly Right]] since while it does make him much more powerful, Superman's temper is temporarily out of control (because, well, it is fire from ''Apokolips''). Franchise/TheFlash becomes the new [[TheGrimReaper Black Racer]] after he kills the old one (namely, he was trying to convince Barry to take his place and required him to offer one life. When Barry initially refuses, the Black Racer threatens to give it to Reverse Flash or Grodd, thus Barry uses ExactWords and kills the Black Racer... before offering ''himself'' as said life.) Subverted with Hal Jordan. He becomes the New God Of Light at behest of the Mother Lantern (the Mother Box fusing with the Green Lantern core, but lacking a vessel for will to use). Hal brings back everyone killed during Apokalips' invasion of Oa, but he gives up godhood when he realizes it would mean giving up will.
* Dr Manhattan in ''Comicbook/{{Watchmen}}'' is a subtler and relatively benign variation of the trope; it's implied that he was more at home dealing with elementary particles than other people even before the FreakLabAccident turned him into an [[WeAreAsMayflies immortal]] PhysicalGod who can see the future [[YouCantFightFate but not change any of it, even]] ''[[YouCantFightFate his own actions]]''. However, instead of suffering a spectacular HeroicBSOD and subsequent FaceHeelTurn, he's one of the least emotionally damaged people in the entire cast, whilst still being [[BlueAndOrangeMorality almost entirely disconnected from normal human thought patterns]].

!!!Franchise/MarvelUniverse
* The evil and non-evil versions of insanity pop up in a ''lot'' of the Marvel Universe's more powerful human characters, apparently as a way of HoldingBackThePhlebotinum. ComicBook/ScarletWitch, Phoenix, Comicbook/TheSentry, or anyone else like that being able to use their maximum power levels while fully themselves would remove all drama. Scarlet Witch is currently the most powerful and resultantly has it the worst. We haven't seen her mind in stable condition for quite some time now that her power's gone from "[[WindsOfDestinyChange I point and my opponent slips on a banana peel]]" to "[[RealityWarper whatever I decide simply]] ''[[RealityWarper is.]]''" She'll ''never'' get to have that kind of power and the ability to think "Wouldn't it be nice if the Skrulls (okay, except [[Comicbook/{{Runaways}} Xavin]], [[ComicBook/FantasticFour Lyja]], and [[ComicBook/XMen Cadre K]], and the Super Skrull if [[HeelFaceTurn he keeps playing nice]]) turned into rice pudding?" at the same time.
* When the Canadian government was looking for people to join Comicbook/AlphaFlight, they initially had trouble finding recruits. The people in charge of the program decided to try creating their own superbeings, and they got the bright idea to experiment on a SerialKiller who got a pardon in exchange for agreeing to participate. The result was a crazed monster with deadly psychic abilities calling itself Bedlam. Franchise/{{Wolverine}} had initially signed on to join Alpha Flight, but this debacle was what caused him to leave the group in disgust. Fortunately, Guardian left an emergency protocol that would automatically call Wolverine should Bedlam be freed, which proved necessary when a government official unfamiliar with the backstory ended up setting him free.
** Madison Jeffries, a {{Technopath}}, and his brother Lionel, a doctor with HealingHands, fought in a war together, where Madison could forget about his mutant powers, while Lionel used his to heal wounded soldiers. Then one day, some soldiers were brought back [[AnArmAndALeg in pieces]]. Lionel attempted to put them back together, and when he couldn't bring them BackFromTheDead, he went insane and started using his powers to [[BodyHorror mutilate everybody within arm's reach]], becoming Scramble the Mixed-Up Man. Madison had to use his powers to create a containment suit for his brother, and had him locked away, completely isolated from human contact. Scramble was eventually able to [[HealThyself seemingly fix himself by using his powers on his own brain]], but it was a temporary fix at best, and his lack of ethics helped to push him around the bend again, forcing Madison (now using the Box robot) to put him down for good.
* All attempts to replicate the SuperSerum that gave ComicBook/CaptainAmerica his powers have [[PsychoSerum either made people go crazy]] or been used on someone who was already crazy. In fact, in the Comicbook/{{Ultimate|Marvel}} universe, this seems to be the origin for all of [[Comicbook/UltimateSpiderMan Ultimate Spider-Man's]] RoguesGallery. One of the rare ''good'' endings for someone getting the Super-Soldier serum is Isaiah Bradley, grandfather of Patriot from the ''ComicBook/YoungAvengers''. Instead of going crazy with power, he simply lost a lot of his intelligence, sort of a super-Alzheimer's. Yes, that's what passes for a good ending when trying to reproduce the Super-Soldier serum. One wonders why they keep trying.
* SelfDemonstrating/{{Deadpool}} was probably messed up before developing terminal cancer, but the Weapon X program (which initially ''failed'' to give him a HealingFactor) gives him a hard shove in that direction. Then Dr. Killebrew experiments on and tortures him to the point of having visions of (and ''falling in love with'') [[TheGrimReaper Death]]. What finally demolishes his sanity is when Killebrew orders him killed, his healing factor finally kicks in, saving his life, making his disfigurement permanent, and causing Death to reject him. Depending on the writer, he's a mix of AxCrazy, DeadpanSnarker, gleeful GenreSavvy, and MediumAwareness. Another issue is that the HealingFactor is connected to his cancer -- he's basically an immortal living cancer. The constant state of flux and strain this places on him (including his brain) is why he's so unstable.
* ''Comicbook/IncredibleHulk''. The gamma bomb gave Bruce Banner huge power and exacerbated his multiple personality syndrome. Plus, the madder he gets, the stronger he becomes.
** Interestingly, for both ''The Mask'' and Marvel's gamma ray mutants, what happens to the subject's mind depends on what part of their personality they had dissociated themselves from. Most people who get the Mask unlock their evil side, but the fellow in TheMovie didn't ''have'' an evil side, only a chaotic side, so he essentially became a WesternAnimation/LooneyTunes character. Marvel goes into more detail -- Banner suppressed the rage that came from being abused as a child, Comicbook/SheHulk suppressed [[MsFanservice her sexuality]], Doc Samson suppressed his desire to be a hero, and the Abomination suppressed his self-hatred.
* Handled interestingly with [[Comicbook/TheSentry Sentry]]. His [[SuperpowerLottery powers]] are like some ridiculous combination of {{Franchise/Superman}} and [[ComicBook/FantasticFour Franklin Richards]], making him technically unstoppable and all-powerful. He's also a paranoid schizophrenic who managed to convince himself that there was an evil galactic power called The Void that would destroy the earth if he stayed a superhero... and then ''actually created it out of thin air'', making a problem for ComicBook/TheAvengers to handle while ComicBook/EmmaFrost gave him some emergency psychotherapy. During this time, he also managed to {{Retcon}} himself out of his own universe, so that his [[UsefulNotes/TheGoldenAgeOfComicBooks Golden Age]] exploits all became some comic writer's fantasy. In something of a subversion, Sentry's not a villain: in current canon, he works to use his powers for a great deal of good. Unfortunately, his psychosis still isn't fully under control, and it's a disability that is sometimes just impossible to work around.
** Later developments suggest that the Sentry is an inversion of this trope. Robert Reynolds was ''already'' a mentally unstable drug addict ''before'' taking the serum that gave him his powers, so it's more like someone with great insanity given great power. Furthermore, [[spoiler:Reynolds didn't become the Sentry and create the Void, it was the other way around..]].
*** [[spoiler:An alternate interpretation is that Reynolds splits into the Sentry and the Void, neither of which are more physically or psychologically real than the other.]]
*** As of ''ComicBook/UncannyAvengers'', he returned as the Horseman of Death (the Void apparently got bored and wandered off), even crazier than ever.
* ''Franchise/SpiderMan'':
** If you're a scientist introduced by name in the Spider-Man comics, you're usually one issue away from your experiments turning you into a deranged {{Supervillain}}. Especially if [[StevenUlyssesPerhero your name conveniently sounds a lot like the type of experiment you're conducting...]]
** In almost every incarnation of Spider-Man, when he gains access to the power-enhancing abilities of the symbiote, he ends up becoming irrationally angry and cocky. Or, in the case of ''Film/SpiderMan3'', an emo. Interestingly, this doesn't actually apply to the original comic book version of Spider-Man; he wore the symbiote suit for about a year without any ill effects, and it wasn't until [[DoesThisRemindYouOfAnything the suit wanted their relationship to be a little more intimate than Spidey was ready for did he realize it wasn't such a great idea]]. The [[WesternAnimation/SpiderManTheAnimatedSeries '90s cartoon]] was [[LostInImitation responsible]] for the "symbiote makes you a psychopath" aspect, [[RetCanon which eventually came into play in the comic universe.]]
** Spidey's ArchEnemy, the [[ComicBook/NormanOsborn Green Goblin]], in his original portrayal, was this. He was a [[ParentalNeglect distant father]] whose business practices were not always [[CorruptCorporateExecutive scrupulous]], but he had redeeming traits, such as genuinely loving his son, and saving Gwen Stacy's father's life. Then the formula that gave him his powers drove him insane, though periodic bouts of amnesia restored him to his former self. After he [[MoralEventHorizon killed Gwen Stacy]], however, he was rewritten as always being sociopathic, with the kinder personality that he possessed during his periods of amnesia being a false personality. The Goblin formula probably enhanced his insanity, however.
* Apparently, Creator/ChrisClaremont likes this one, or used to. In ''Comicbook/XMen'', The Phoenix being a cosmic entity was a {{Retcon}} to satisfy the then-editor-in-chief's requirement for bringing ComicBook/JeanGrey back: she had to be innocent of her crimes as Phoenix. (The destroyer of five billion lives couldn't very well be welcomed back to the team with open arms. In fact, her original HeroicSacrifice was ''mandated'' for [[RedemptionEqualsDeath that very reason]].) The original story portrayed Jean's cosmic powers as the ultimate expression of her abilities, and the change from hero to AntiHero to cosmic-scale threat as simply the result of having the sort of powers she now possessed. Comicbook/{{Storm}} also began a similar change upon maxing out her powers, but thankfully was able to return to her previous self (her power level returning to normal with it) within that issue and before she did anything particularly heinous.
** The 'return' of Comicbook/JeanGrey in the ''ComicBook/XFactor'' retread of the original Comicbook/XMen was so badly done that it left ''permanent'' damage to the storylines of the Marvel Universe. The obvious moral cop-out of 'it wasn't really her' not only undid the basic ''point'' of one of the landmark storylines of the MU, but was done in a half-assed way, because they tried to claim that Jean deserved the credit for the self-sacrifice of the Phoenix entity, but not the blame for its crimes, even though both supposedly derive from the human element from Jean. Sorry, folks, you can't have that both ways.
** To make it even worse, Claremont clearly hated the idea that the Phoenix entity was not Jean, he kept trying to sneakily [[CharacterRerailment re-retcon it back]], and the story got into the hands of other writers and mutated further, eventually becoming a total, unworkable, self-contradictory ContinuitySnarl. Nowadays, it's mostly ignored.
** Oddly enough, though, Jean's [[KidFromTheFuture time traveling daughter]] ComicBook/{{Rachel|Summers}}, who ''already'' had [[TraumaCongaLine ample reason to have gone insane]] (but didn't) ''before'' acquiring the Phoenix power, managed to wield it for ''years'' without going crazy. And then lost the power (despite the Phoenix itself insisting that it had ''permanently'' merged with her).
** Long story short, Jean's power level, mental state, and the effect these have on each other ''all'' depends on where Jean ends and the Phoenix begins. Too bad no two mentions of the Phoenix in a row give the same answer on that score. However, the cosmic critter isn't malevolent. ''Mastermind screwing with her head'' was what turned Phoenix into Dark Phoenix, and to suggest it ''might'' happen again much later in ''Phoenix: Endsong'' took a botched resurrection to again put the Phoenix out of whack. Poor Jean will NeverLiveItDown, despite this.
*** Speaking of Mastermind and his plan to gain power through unleashing the Dark Phoenix, as Jean lost her mind and became the Dark Phoenix for Mastermind's evil means, [[EvilIsNotAToy she turned on him]] and [[BeCarefulWhatYouWishFor ironically, gave Mastermind more power than he could ever comprehend,]] sending him into a coma (and insanity when he came to).
*** Oddly enough, Jean and her relatives actually tend to handle vast/cosmic scale power pretty well, Phoenix saga aside. Jean spent most of the 90's and early 2000's being incredibly powerful under her own steam, and her teenage counterpart has largely kept her powers in hand too. Meanwhile, her children, ComicBook/{{Rachel|Summers}}, [[ComicBook/XMan Nate]], and ComicBook/{{Cable}}, are all vastly powerful (intermittently, in Cable's case, and sometimes Nate's) and entirely sane. Usually. Cable seemed to undergo this when his Techno-Organic virus went into remission and he created the floating island of Providence, jacking him up to the point where he could fight the Silver Surfer on even footing, hold Providence in the air, and repair the landscape around them as they fought. As it turned out, however, it was a GenghisGambit to get the world to unite against him. Nate, meanwhile, lived in mortal terror of a combination of this and lethal cosmic scale PowerIncontinence, but largely held it together pretty well - which, for a LivingWeapon who had no functional childhood, grew up in the hell that was the ComicBook/AgeOfApocalypse, had to live with the knowledge that he was slowly dying, and had just about everyone trying to manipulate or destroy him once he got to 616, is really quite impressive. As for Rachel, of the lot of them, she's by far the sanest.
*** Then in ''ComicBook/UncannyXMen2018'', Nate appeared to a) regain his powers and then some, b) lose his marbles and declare his [[AGodAmI status as a god/messiah]]. Considering his status as a MessianicArchetype and raw power, it's a bit hard to argue with. However, it's revealed at the end of the arc that [[spoiler: he got his powers back, but at the price that he's dying, again, and he's desperate to do something good with his powers while he can]].
*** He then created the ComicBook/AgeOfXMan, a plane of existence meant to be directly opposed to [[ComicBook/AgeOfApocalypse the dystopia he grew up in]], an attempt at utopia (specifically, he wanted to help the X-Men by [[spoiler: breaking them out of their constant cycle of conflict and grief]]). Unfortunately, through a combination of his ControlFreak tendencies, attempts to disassociate himself from humanity, and screwed up background, it instead drifted far too close to a [[CrapsaccharineWorld creepily cheerful]] ''Literature/NineteenEightyFour'' clone. At the end of the arc, he conceded his mistakes and realised that he was NotSoAboveItAll (though the comic noted that BothSidesHaveAPoint) and let the X-Men go, before rewriting the reality with the assistance of [[spoiler: AOX!Magneto]] to improve it and remove the Orwellian aspects.
*** While Stryfe and Maddie Pryor are worth noting, both were clones - Stryfe remains in denial about this, while Maddie did ''not'' take it well - and Stryfe was raised by Apocalypse, while Maddie was created by Sinister as his weapon with cobbled together memories from Jean Grey. Their insanity was not exactly of their making.
*** This trope as related to the Summers family is further deconstructed in the character of Tyler Dayspring, son of either Cable or Stryfe (raised by Cable, but it's heavily implied that Stryfe is his true father). Like Stryfe and Maddie above, Tyler lost his sanity through means not of his own making (he was brainwashed in the future by one of Stryfe's minions) -- but unlike them, he has very weak mutant powers, to the point of needing to augment himself with Apocalypse's technology just to stand a chance against the heroes. In a way, Tyler got the rawest deal out of the entire Summers line -- all the insanity of this trope without any of the power.
** Claremont also established that classic X-Men adversary ComicBook/{{Magneto}}'s magnetic powers damage his sanity over time. This explains rather a lot; wouldn't being able to control one of the four fundamental forces of the ''universe'' screw you up, too? [[RedemptionDemotion This is also why he's generally a lot weaker at times when he's a good guy: he's got to hold back in order to avoid having another case of megalomania.]]
*** Some writers have tried to pull the same thing with Havok (Cyclops' brother), who controls (or at least, has a degree of access to) the Power Cosmic, ''another'' fundamental force of the Marvel universe. This is made apparent with the introduction of [[spoiler:the long-anticipated third Summers brother Vulcan, who has near-Phoenix level command of the Power Cosmic (and would be near-Phoenix level dangerous if he had more than two brain cells to rub together) but at the cost of being completely off his rocker]].
** Magneto comes close to saying this trope by name in issue two of the nineties X-Men series. When Moira [=MacTaggert=] explains how his powers played havoc with his mind, he states: "What, with great power comes mental instability?"
*** Magneto's daughters, ComicBook/{{Polaris|MarvelComics}} and the Comicbook/ScarletWitch, suffer from similar sanity-damaging "{{cursed|WithAwesome}}" powers. Insanity might be InTheBlood where this family's concerned.
*** It's implied that the Scarlet Witch's crazy came from the MindScrew the Avengers did so she'd [[spoiler:forget her maybe/sort-of/magic children]] rather than from her powers themselves. Similarly, Polaris is only crazy when outside influence is involved... it just happens to her more often than it does to anyone else.
** While not part of Magneto's family per se, a special mention should be made for his [[TheDragon Dragon]] and intended successor from the 90s, [[Characters/XMenAcolytes Exodus]]. He has psychic ComboPlatterPowers ramped up to SuperpowerLottery levels, but unlike most mutants, who manifest by puberty, his powers didn't manifest until adulthood, and then not until being forcibly awakened by ComicBook/{{Apocalypse}}. The result is a character who projects constant wide-band PsychicStatic where he goes, was implied to always be speaking telepathically and physically ''simultaneously'', and at one point was even implied to suffer from a psychic variant of schizophrenia because his telepathy was so strong. He's developed greater control of it over the years, but even as recently as 2012 it was stated that he had never actually pushed the upper limits of his powers.
*** In the ComicBook/AgeOfApocalypse this trope is inverted, as the Exodus there is shown as wearing PowerLimiter devices and not being aware of a good chunk of what he can do until a GodzillaThreshold forces Magneto to reveal some of it to him. When questioned by Bishop, Mags stated outright he limits Exodus's knowledge of his powers to keep him from being corrupted by them.
** This was {{lampshade|Hanging}}d in the ''Assault on Weapon Plus'' story arc, where the Weapon Plus files stated that super soldier experiments on criminals and psychopaths yielded less than reliable results, prompting them to find a different method of creating anti-mutant super soldiers.
** Another X-related example has to do with [[Characters/{{Wolverine}} Omega Red]], the [[UsefulNotes/SovietRussiaUkraineAndSoOn USSR's]] attempt to engineer its own ComicBook/CaptainAmerica-like super soldier. [[IdiotBall The brain trust in charge of the program chose a]] SerialKiller [[IdiotBall who'd been shot by his fellow soldiers for murdering children in his hometown.]] While initially a loyal operative, he eventually became too AxCrazy even for the KGB and was put in suspended animation, at least until the Hand freed him. He now functions as a PsychoForHire and one of the X-Men's deadliest foes.
* In ''[[Comicbook/TheNewUniverse newuniversal]]'', which is also by Creator/WarrenEllis, John Tensen gains telepathic powers that let him "see" a person's misdeeds or ignoble intentions. The first time he used these abilities, he discovered that his own nurse was planning to poison him. Tensen, not surprisingly, became AxCrazy and is now the "worst serial killer in New York City history," to quote a minor character. It doesn't help, though, that Tensen had been shot in the head before he got his powers, and as a result starts to think he's in Hell.
* ''ComicBook/{{Nova}}:'' The Nova Force is dangerous in large amounts. At one point Garthan Saal takes on the entirety of the Nova Force, and goes completely bug-nuts. It's because of this that several years later, during ''ComicBook/{{Annihilation}}'' Richard Rider is extremely reluctant to do the same. The Xandarian Worldmind has to assure Rich it'll be helping to prevent that happening, and aside from a brief, trauma-induced rampage, Rich remains mercifully un-insane. [[spoiler:But as it transpires, the strain drives the Worldmind mad. When asked, a saner part of it just shrugs and figures Rich is too human to go nuts.]]

!!!Other
* Apparently, getting hopped up on Chaos Emerald Energy in ''Comicbook/ArchieComicsSonicTheHedgehog'' series makes you do crazy things. Examples:
** Knuckles' ancestor Dimitri ends up becoming the insane Enerjak after absorbing 11 Chaos Emeralds worth of power, one of the most powerful and evil villains in the series. A later retcon revealed that Enerjak was an echidna who grew mad with power after [[AscendToAHigherPlaneOfExistence ascending to a higher plane of existence]] and, unable to destroy him, scattered his essence throughout the Chaos Force, allowing him to inhabit future echidnas who used Chaos powers.
** Knux's dad Locke, obsessed with the prophecies surrounding his son, genetically engineered himself and infused Knux' egg with energy from the Master Emerald in an attempt to fulfill those prophecies. They're more or less estranged, now, because of this.
** Knux himself isn't safe from this, having appropriated Dimitri's mantle of Enerjak to avenge his race's decimation at Eggman's hand, only to quickly degenerate into "technology = evil" and attempt to wipe out all cybernetics from the planet, including those of the Dark Legion and his own girlfriend Julie-Su. This was caused by Dr. Finitivus, a scientist who tried to drain Knuckles' Chaos power earlier, only to have it backfire and transform him. He then decided to go and screw over the entire echidna race by deciding everyone needs to die in a fire.
*** In the ([[CanonDisContinuity non-canon]]) "25 Years Later" storyline, Knux ends up becoming "Chaos Knuckles" (a form he took up in the normal canon without much ill effect), and ends up trying to change the world, as well. The result was the almost complete destruction of his friendship with Sonic and the loss of his right eye.
*** In the future of an alternate universe, Knuckles not only tried to change the world, but he succeeded in conquering it after harnessing the power of all the emeralds. [[YourSoulIsMine He ripped the souls out of nearly all the main characters]] (Eggman, Sonic, Shadow, Tails, his own mate, etc.), sunk a continent, and then decided to try and amuse himself by conquering other dimensions. He uses the souls of his victims to create his Prelate Army. Oh, and he took on the name Enerjak in this timeline because "Enerjak the Hero" sounded cool.
** Some versions of Sonic's Super form are like this, becoming a SuperpoweredEvilSide. The best example of this is the British comic by Fleetway, in which Sonic and Super Sonic are [[JekyllAndHyde separate personalities]], and Super comes out to play when Sonic gets too stressed out or is exposed to Chaos energy.
*** Then there's the third season of Sonic X. Seeing [[spoiler:Chris and Cosmo held hostage and trapped in a glass cage]] gives a view of [[BerserkButton how upset Sonic gets]] when [[spoiler:his friends are harmed]]. Combined with the 500-odd fake Chaos Emeralds nearby, Sonic turns Dark Super, shredding two test robots (based on speed and power respectively) in the blink of an eye, complete with the ''slightly unhinged'' giggle and a "Alright, Let's try 'em out!". It took a minute and Eggman's logical prose to snap Sonic out of it, surprising somewhat as they've been at each other for years, and Sonic could quite easily rip Eggman to gibs.
*** In Archie canon, Super Scourge (Scourge being [[EvilTwin an evil version of Sonic]] who is already hyped on Master Emerald energy, so this makes him even worse than a standard super form), upon seeing that his own world (which he conquered) nor Sonic's own will accept him as King, says he's going to '''spindash''' both worlds in half just because he can, and will do this to one world after another until one gives him "the respect he deserves."
** Sonic from the games actually becomes kind of crazy when he turns into Super/Hyper Sonic, at least in the old-school games on the Genesis. Suddenly goes from fast and cocky but vulnerable to fast and cocky and ''in''vulnerable, tearing through anything in his path. And way, ''way'' harder to control.
** Back to the Archie comics: On Mobius Prime, when Amy Rose used the Ring of Acorns on herself, she became her older ''VideoGame/SonicAdventure'' self. On the MirrorUniverse world of Moebius, when Anti-Amy did it, she went certifiably ''insane''.
* Inverted ([[ZigZaggingTrope or not]]) in ''Comicbook/TheAuthority'', where the Doctor gives up his powers to a [[LegacyCharacter previous]] Doctor, who was relieved of his duties for being a [[OmnicidalManiac psychotic maniac]]. As soon as the full extent of his powers kicked in, he was [[VillainousBSOD overwhelmed]] by the empathy for every living thing in existence. Super-empathy being part of the Doctor's role as the world's shaman, makes you wonder why this guy was psychotic [[FridgeLogic in the first place]].
** Every Doctor gets a new power, added to the ones the previous Doctor who had the job had all the way back to the first one. After he went psycho, the next guy got super empathy, which he used A LOT of heroin to deal with.
* Creator/WarrenEllis' ''Comicbook/GlobalFrequency'' not only invokes this, but explains it in terms of the surgical alterations required to keep the superstrong bionic arm or whatever from physically tearing the body apart. "They gave him a mirror."
* In ''ComicBook/GoldDigger'', dragon hybrids between the tribes (Platinum, Gold, Copper, and Iron) are extremely rare and extremely powerful. Every single one has gone insane, however, with the sole exception being one of the comic's supporting cast, D'bra. And then, most dragons believe her temper is a sign that it's only a matter of time.
* In ''ComicBook/{{Hellboy}}'', losing control of one's powers and/or humanity was a major theme of the series, especially for Liz Sherman and Hellboy himself. That is to say: Liz burned her family to death by accident as a kid, and Hellboy doesn't and can't and won't use his flashier superpowers, since they mostly involve ending the world, but occasionally they get stolen, one way or another. His crown, his Name, his right hand, ALL THE BLOOD IN HIS BODY...
* A rather mundane case of this appears in ''[[ComicBook/{{Irredeemable}} Incorruptible]]''. Max Damage becomes [[SuperStrength stronger]] and [[NighInvulnerability more invulnerable]] the longer he stays awake. If he stays awake for say, a week, his powers reach PhysicalGod levels. However, he is still vulnerable to the effects of sleep deprivation. The result is someone who is mentally exhausted and strong enough to topple buildings -- an unnerving combination. Dealing with the numbness his invulnerability brings with it for years has also taken its toll on Max's sanity. Given that the premise of the story is Max's attempt at a HeelFaceTurn to save the world from an [[BewareTheSuperman evil Superman]] {{Expy}}, this causes even more problems. He needs to be strong enough to fight the Plutonian yet not let his insanity push him back toward a life of evil.
* ''ComicBook/TheMask'' is this trope. Summary of every Mask story: Person finds the mask, puts it on, discovers they're a {{Nigh Invulnerab|ility}}le VoluntaryShapeshifting RealityWarper, starts using their powers in pursuit of some logical goal, loses sight of their goal and engages in wanton violence ForTheEvulz, is either tricked into removing the mask or removes it after a WhatHaveIBecome moment.
* In ''Comicbook/{{Powers}}'', a naturally occurring variant occurs in "The Sellouts" storyline, in which a never-aging CaptainErsatz of Franchise/{{Superman}} gradually loses his connection with humanity and goes insane, [[AGodAmI declaring himself to be a God]]. It's discussed that this may partly be a result of his ever-increasing level of superpowers, which go ''way'' beyond anything seen before (to the extent that the government has lied about exactly how powerful he is in order to prevent hysteria about him), and partly because, despite the fact that he doesn't ''look'' very old, he's at least over a hundred years old and has gone senile.
* ''ComicBook/{{WITCH}}'' has the Heart of Kandrakar, an artifact of immense power that may drive its Keeper mad just by being ''that'' powerful. While the protagonist, Will, is a sane and well-adjusted person and her [[ClingyJealousGirl extreme jealousy]] has a good FreudianExcuse, the BigBad of the second story arc was the previous Keeper and ''has'' been driven mad, and Will has the occasional moment of slight (and useful) madness.
* In ''ComicBook/{{Zenith}}'', the alternate Earth Maximan, who had been superpowered since the 40s, ended up going completely insane and killing everyone on his version of Earth. That said, most of the '60s superheroes became somewhat less than rational by the time of the early '90s.
* In the original Creator/{{Wildstorm}} continuity, ComicBook/{{Grifter}} spent several years suffering from mental illness after being exposed to Gen Factor before Zealot helped him regain his sanity.
[[/folder]]

It seems like any major military- or corporate-backed venture to give a [[{{Muggles}} mundane person]] [[StockSuperPowers super powers]] or just enhance their [[BadassNormal normal abilities]] results in the test subject going [[PsychoPrototype uncontrollably berserk]] as a [[GoneHorriblyWrong side-effect.]]

Sometimes the choice of test subject is clearly to blame. Convicted criminals are convenient ("[[BoxedCrook One swallow and ten years go off your sentence!"]]) but unreliable guinea pigs if you're trying to develop a SuperSoldier who can punch out a tank. Nobody in any of these programs ever seems to have been given the [[ThereAreNoTherapists most basic psychiatric evaluation.]] The evidence indicates a connection between morals and one's ability to remain "sane." Normally, using the power makes you crazy the longer you use it, because EvilFeelsGood, but a noble, heroic character is [[HeroicWillpower better able to stay in control.]]

Sometimes, the creators of the super being realize the error while in the prototype phase and will [[SealedEvilInACan seal the subject away]], hoping everyone just forgets about them. Often, the [[SuperPrototype first subject]] to undergo the process -- or a single subsequent subject -- will [[PhlebotinumRebel turn out okay]], so on top of all the various other issues that the treatment has, it's usually their job to clean up the mess made by subsequent failed attempts. If it's a ScienceIsBad story, the sponsors of the program are likely to just keep pumping out nutty prototypes hoping they'll eventually make one that is ''not'' insane.

[[folder:Anime & Manga]]
* Anime classic ''Manga/{{Akira}}'' centers around the results of government experimentation on a Japanese gang member with a serious inferiority complex. As a result, the newly created BigBad Tetsuo runs amok with his telekinetic powers until he mutates, explodes, and forms either a new universe [[GainaxEnding or... something]].
* In ''Manga/{{Berserk}}'', the main character finds that he can enter into an UnstoppableRage like never before due to his recently obtained UpgradeArtifact. However, he finds himself BlessedWithSuck due to the [[PowerDegeneration incredible physical strain it puts on his body]], and he could [[TheCorruption accidentally]] FaceHeelTurn at any moment and kill all of his companions.
* In ''Anime/TheBigO'', StrawNihilist villain Schwarzwald is the only known character to figure out the big secret. As a result, he goes batshit insane, wraps himself up like a mummy, and spends the rest of the series raving about philosophy, leaving typewriters lying around everywhere he goes, and [[spoiler:showing up in a robot several weeks after his death to chew out another villain who gets killed trying to use it]].
* In ''Manga/{{Bleach}}'', Ichigo's powers are greatly amplified when his [[SuperpoweredEvilSide inner Hollow]] is released, but he suppresses it in order to preserve his sanity. Even then, suppressing it doesn't work in the long run. It takes a major BattleInTheCenterOfTheMind for him to gain control over it. [[spoiler:During the third battle, the Hollow isn't trying to hurt Ichigo, his goal is to make Ichigo accept him as part of his soul instead of suppressing him. Once Ichigo does that, he becomes a PhysicalGod.]]
** Aizen has never been entirely sane, but his insanity slowly becomes more and more obvious the greater his power becomes. [[spoiler:By the time he's fused with the Hougyoku, he's fullblown crazy.]]
** Kouga (from the third anime filler arc) fits this trope perfectly. His power ([[spoiler:to force others' zanpakutou to do his bidding]]) is truly enormous, and he quickly goes insane. Kouga had plenty of external help on that trip to insanity, but his obsession with his own great power made him a little unbalanced even when he was still one of the good guys.
* Human-type homunculi of ''Manga/BusouRenkin'' are a borderline example, as while becoming a homunculus does grant a human great power, none of the ones seen seem like they were particularly sane beforehand. Victor, though, is a dead-on example, as becoming a Victor made him do a FaceHeelTurn from an alchemic warrior to a demigod attempting to destroy all alchemy.
* In ''Manga/ChronoCrusade'', Joshua Christopher is given the horns of a demon by the BigBad. The power is too much for the small boy, however -- within minutes he's gone completely insane, using his powers to freeze everyone around him in time and destroy the orphanage he lived in. It gets '''so''' bad that later [[spoiler:he can't even remember his own sister]].
** It's even worse than that in the manga. [[spoiler:It turns out that a demon's horns, in addition to granting them direct access to the Astral line, are also what connect them to their "mother", Pandemonium.]] That constant, painful noise that Joshua was complaining about? [[spoiler:It was an EldritchAbomination ''constantly [[MindRape mind-raping]] him.'']]
** In the anime, though the horns did damage his mind on their own, the "noise" he complained of was the thoughts of every human around him. In other words, uncontrollable telepathy that forced him to hear what every single person around him was thinking, all at once, all the time. No wonder he went mad if he had to be near people.
* ''Manga/{{Claymore}}'': A Claymore who activates her demonic powers (i.e. "Awakens") gains great power but stands a chance of losing her humanity and turning into a human flesh-craving demon permanently.
* ''Anime/CowboyBebop'', "Pierrot le Fou": A government test subject is given superhuman assassin skills, and then goes crazy as a side-effect. Given [[PlayingWithSyringes the methods shown]] (the fact that no explanation of any sort is given for what, precisely, is being done, it's all the more disturbing), it's not too surprising.
* ''Manga/DNA2'' has TheRival become the BigBad when he gained the power to "absorb other people's DNA". Don't ask how that works or why it gave him a BattleAura and shapeshifting powers, [[HandWave it just did]].
* Contractors in ''Anime/DarkerThanBlack'' appear to have "complete lack of conscience" as one side-effect of gaining their powers (and their powers are usually destructive in nature). Even the sanest among them are AffablyEvil or {{Anti Hero}}ic at best and have no problems with taking lives, though whether it is the powers themselves that cause it or the result of the extensive {{masquerade}} surrounding them and how their fellow humans treat them is up to debate.
* ''Manga/DeathNote'' drops some hints that Light Yagami wasn't entirely stable ''before'' gaining the power to kill anyone in the world at any time, but his sanity certainly [[AGodAmI heads downwards]] after that. In fact, ''all'' the Kiras in the series seem to go bonkers after picking up a Death Note, since it seems to take the major flaw in their personality and magnify it -- Light and Takada's narcissism, Mikami's fanatical desire for justice, Misa's obsessiveness, and [[spoiler:Higuchi]]'s greed.
** It even says in chapter 19 that "with great power comes great...evil!?" which is pretty darn close, in Light's case.
** When he briefly lost his memories of the Death Note as part of a MemoryGambit, he immediately becomes a NiceGuy that has almost nothing in common with "Kira", to the point that he finds the very notion that he might have been "Kira" to be horrifying. [[MurderMakesYouCrazy The shock of his first kill]] and the resulting god complex he manifested to avoid the guilt really messed him up.
** Near casts some doubt on this in his TheReasonYouSuckSpeech to Light, claiming that a sane and decent person would use the Note out of curiosity, be frightened by the consequences, and get rid of the Note out of regret. A sane and evil person would use it for self-interest. Light on the other hand deluded himself into believing the Note made him a god.
* In ''Manga/DevilmanLady'', the entire story centres around evolution and the gaining of vast, beast-like powers by ordinary people, many of whom go insane. The main character, Jun, for much of the series appears to be descending into insanity herself despite her best efforts not to. The climax moment of this aspect of the series is when, having been prevented from indulge her bloodlust by the Human Alliance, she attacks a nurse, but ultimately overcomes her instincts by drawing her own blood.
* Both played straight and averted in ''Franchise/{{Digimon}}''. On the one hand, you have Digimon like Omnimon, who are immensely powerful, but perfectly sane, noble, and benevolent. On the other hand, you have Beelzemon and Diaboromon, who are driven only by their desire to gain power and cause destruction.
** Myotismon is already incredibly powerful, but becoming his mega form, the colossal [[OneWingedAngel VenomMyotismon]], turns him from TheChessmaster to an all devouring mindless monster.
* ''Franchise/DragonBall'':
** The ''Anime/DragonBallZ'' movies have Broly who became a berserker warrior because he was born with immense power. It is also heavily implied that the life-threatening experiences of his childhood also contributed quite a bit to his insanity as well.
** It's all but stated in the manga that reaching new levels of Super Saiyan cause Goku and Gohan to become more aggressive and ruthless, which is particularly jarring to the other characters (Vegeta was already pretty bad, so he just gets more and more arrogant). Vegeta says that to become a Super Saiyan, you must have a pure heart (pure evil or pure good doesn't seem to matter) and be in a state of pure rage, with (except for [=SSJ3=], which is achieved off-screen) the new levels involving them getting more enraged than they have ever been before. While this doesn't last, and any future transformations allow them to stay 'normal' it is still pretty unclear how changed they are as a result of this brief spurt of maddening rage. Basically, at each newer Super Saiyan level, they tend to revert to the typical Saiyan brutality. Vegeta doesn't have any similar problem because extreme brutality is his default state.
** Gohan is truly shocking in his beatdown of Cell as he goes from restraining himself because he doesn't want to fight to torturing Cell in the space of a few minutes. Even Goku is shocked by what the transformation does to his son.
** In ''Anime/DragonBallGT'', Goku loses his reason and turns into a giant, supremely powerful golden ape when he first transforms into a [=SS4=]. This was simply the latest in a long list of giant ape transformations from ''Manga/DragonBall'' and early ''DBZ'', which had the same effect: multiplying the Saiyan's power level by a factor of 10, but causing their minds to become animalistic. Vegeta was the only one to remain sane in this form... presumably due to actually being trained in its use.
** Frieza's reason for using transformations to hide the bulk of his power is heavily implied to be due to losing what little sanity he already had if he went all out.
** [[spoiler: Infinite Zamasu]] from ''Anime/DragonBallSuper''. Completely unkillable, and when they ''do'' deal with him, he [[spoiler: becomes the ''entire'' multiverse of the Future Trunks timeline]]. Also entirely irrational, and can do little more than destroy everything he can and laugh. Downplayed in the manga, since he just gains the ability to clone himself indefinitely and remains as sane as before... which ''[[OmnicidalManiac really]]'' [[AGodAmI isn't]] [[BlackAndWhiteInsanity saying]] [[TautologicalTemplar much]].
* Any Diclonius in ''Manga/ElfenLied'', except Nana. [[spoiler:Maybe. It's heavily implied that their murderous tendencies might actually be a result of abuse, particularly at the Institute. Might. It's ultimately left ambiguous.]]
* ''Manga/FairyTail'':
** This was the result of Elfman's failed Take Over spell against a monster called The Beast a few years before the story started. In order to save his older sister, he used his magic on a gigantic magical monster, but wasn't quite strong enough to control it. He saved his older sister, and killed the younger [[spoiler:they thought)]]. Out of fear of this happening again, he stopped using full-body Take Over magic (eventually, he becomes able to control his power).
** It's eventually revealed overusing the power of Dragon Slaying Magic has the potential to do this as it matures and the human gets closer and closer to the power of an actual dragon. [[spoiler:The final stage involves turning ''into'' a dragon and becoming consumed by the god-like power and arrogance it brings. This is how Acnologia went from a NominalHero on a RoaringRampageOfRevenge to an BloodKnight OmnicidalManiac.]]
* In ''LightNovel/FateZero'' and ''VisualNovel/FateStayNight'', Berserker-class Servants get Mad Enhancement, a Class Skill that trades one’s sanity for added power.
* In the first anime of ''Anime/FullmetalAlchemist'', Ed gets a power overload from contact with a huge amount of unfinished Philosopher's Stone and goes full-on uncontrollable with so much power it is described that if this goes on, he can attain enough power to be god-like (even freaking out the Homunculi) until a CooldownHug snaps him out of it.
* Played with in ''Manga/FutureDiary'', where some individuals who're not so mentally sound to begin with are given the ability to predict the future and told by God to kill each other [[ThereCanBeOnlyOne Highlander style]]. Whether the ability, situation, or just generally being that nuts before drives them [[AxCrazy crazy]] is up for interpretation.
* ''Anime/{{Gasaraki}}'' has mecha pilots who were given a cocktail of boosting drugs in order to improve their battle performance (without their knowledge or consent, and said drugs was actually fluid extracted from the muscles of a 1000 year old demon), and the inevitably go berserk from the effects, before either lapsing into a coma or suffering cardiac arrest.
* In ''Manga/GetBackers'', Ginji and [[spoiler:Kazuki]] have this as a side effect of their {{Superpowered Evil Side}}s. Ginji's "Lightning Lord" aspect is quiet, cold, and utterly ruthless, while [[spoiler:Kazuki goes absolutely berserk when he releases the seal on his "Stigma," becoming vicious and blood-thirsty]]. They're always sorry afterward.
* In ''New Manga/GetterRobo'', Ryouma lets himself get hopped up on Getter Energy, powering him and New Getter-1 to new heights to combat the Four Heavenly Kings. However, Ryouma loses himself and Hayato and Benkei have to try to reel him back in before his actions get them killed.
* In ''LightNovel/HaruhiSuzumiya'', the titular character is kept LockedOutOfTheLoop regarding the fact that her friends are all examples of the very weirdness she seeks to find for this very reason. Already a JerkAss {{Tsundere}}, they're afraid that if she discovers that aliens, espers, dimension/time travellers and other such entities are real, she will manage to make the intuitive leap and realise that she is a RealityWarper of such power that she is, in all practical terms, a goddess. Given how much strain she can put on the fabric of reality even while she's unaware of her power, they naturally fear that allowing someone of her attitudes and ethics full control of her abilities would effectively bump her to EldritchAbomination status.
* The previous GameMaster from ''Manhua/InfinityGame'' was driven completely insane by the infinite power he wielded in his world, so he drove everybody else insane and made them kill each other. He eventually grew bored of it and killed everybody.
* Manga/InuYasha's heritage of demonic power from his Greater Demon father is so strong that it is too much for his half-human body to handle. That's why his father created the [[EmpathicWeapon Tessaiga]], to serve as a RestrainingBolt on Inuyasha's demonic power and thus preserve his sanity (while also making up for the power suppressed with the sword's own usefulness). If the sword is taken from Inuyasha or broken, he must refrain from getting too emotionally excited, or he risks unleashing his full, uncontrollable strength. Worse, each subsequent overload renders him more insane than the last, and it becomes harder to snap him out of it. If left unchecked, Inuyasha would eventually be reduced to a mindless monster killing and destroying everything and everyone around him, ''permanently''. Initially, the sword was effective in this role no matter how far away it was, but after it was broken the first time the sealing effect was weakened and even after it was repaired it has to be kept close at hand at all times.
* In ''LightNovel/KumoDesuGaNaniKa'' the Skills corresponding with the SevenDeadlySins ''and'' SevenHeavenlyVirtues grant the bearer powerful abilities and Ruler authority at the cost of slowly warping their soul to reflect the sin or virtue. The only way to avoid this is by not activating the Skill or gaining Heresy Resistance, which reduces the damage to the soul.
* During an episode of ''[[Anime/PrettySammy Magical Project S]]'', Misao dreams about having magic powers and the "fun" she would have using them. When she actually ''got'' said powers, she becomes the arguably insane persona of Pixy Misa (who tortures the entire main cast).
* In ''Manga/MagicalRecordLyricalNanohaForce'', this is happens to everyone who succumbs to Eclipse disease. Aside from AntiMagic and [[HealingFactor insane regeneration]], the Eclipse seems to have a rather [[MindRape detrimental effect on the victim's mind]] by [[TookALevelInJerkass stripping them of their morality]] and them into [[TheSociopath sociopathic]] [[{{Jerkass}} assholes]]. In particularly bad cases, the infectees [[LossOfIdentity completely forget who they are]], picking up FakeMemories in the process. Finally, once they [[DrunkWithPower start abusing their regeneration]], [[PowerIncontinence it goes haywire]] [[AndIMustScream and they become nothing but a lump of flesh]].
* A few of the characters in the ''Manga/MaiHime'' mangaverse are given special earrings created using SEARRS technology, which allows them to summon more powerful [=CHILD=]s than any of the [=HiME=], and they don't need an [[ThePowerOfFriendship emotional anchor]] to use said powers. However, relying on this ability too much can drive them insane.
* ''Anime/MobileSuitGundam'': A common theme in the franchise, most notably ''[[Anime/MobileSuitZetaGundam Zeta Gundam]]'' and ''[[Anime/MobileSuitGundamZZ Gundam ZZ]]'' where all Newtypes are often mentally unstable in some fashion, may have forms of amnesia, be brainwashed, though in some other cases they're just plain stubborn. This is particularly true of "Cyber-Newtypes", people who originally had no special powers but had their brains surgically altered (almost always against their will) to become Newtypes.
** ''[[Anime/MobileSuitGundamSeed Gundam SEED]]'' plays on this by giving [[PsychoSerum performance-enhancing drugs]] and treatments to criminals who are doing it in exchange for a full pardon. Naturally, this drives them to insanity in combat... which is what was planned. As a result, they are given drugs in such doses that by the time combat is over, they are having withdrawal symptoms and are manageable again. Withdrawal will also kill them if they are deprived of the drugs for too long, thus ensuring their loyalty.
** In ''[[Anime/MobileSuitGundamSEEDDestiny Gundam SEED Destiny]]'', Blue Cosmos has been attempting to create "Artificial Coordinators" through depraved combinations of surgery, hypnosis, [[TrainingFromHell insane training]], drugs, and other horrors. Of the dozens of children selected for the project, only a few survived, and those seen in the series are all, understandably, raving mad and almost incapable of functioning normally in life. Without routine "maintenance", their bodies break down and they die. The sad thing is that in comparison to ''SEED'''s pre-Extended (see above), they're all poster children for Mental Health Week: Stellar Louissier, for example, is a sweet [[PsychopathicManchild if incredibly childish]] [[TheWoobie and still very sympathetic]] young woman who loves to dance, as long as you don't [[BerserkButton tell her that either she or her friends will die]], in which case [[SuperpoweredEvilSide an alternate personality emerges that could give even the drug-enhanced pilots of the previous series some lessons in brutality]].
** In ''[[Anime/MobileSuitGundamWing Gundam Wing]]'', the ZERO System gives the person who uses it incredible reaction times and tactical predictions bordering on prescience. The problem is, without any guidance, the System evaluates ''everything'' as a potential threat, and plugs into the user's mind all of the possible attacks that could happen. If he can't focus his mind and give the System the necessary context (which is hard to do when you're conflicted as to why you're fighting), those violent predictions start afflicting whatever he starts thinking about (like, say, his girlfriend, or that nice peaceful space colony over there), and soon enough he's a psychopath slaughtering whatever the System says is his enemy.
** In ''Anime/MobileFighterGGundam'', being infected by DG Cells has this effect. Lower-tier Gundam Fighters like Michelo Chariot, Jean-Pierre Mirabeau and Gentle Chapman (a top-tier Fighter in the past, but one who has aged badly and is addicted to painkillers in the present day) all get massive power-ups after being infected by the Cells, but they all lose their sanity to greater or lesser degrees (Michelo, a malevolent man even before the DG infection, is largely unchanged except for becoming more aggressive and less inclined to self-preservation, while Chapman, a FallenHero, is reduced to a barely-sentient attack dog).
* In ''Manga/{{Naruto}}'', Sasuke seems to grow progressively more irrational the stronger he gets (as, to a lesser extent, do Itachi and [[spoiler:Obito]]). Eventually it's revealed that this is part of how their powers work; whenever a member of the Uchiha clan experiences strong emotion, it creates a burst of energy that increases the power of their Sharingan… and also damages their brain. In short, the best way for an Uchiha to become extremely powerful is to MindRape themselves into oblivion, ''a lot''.
** [[spoiler:The Sage of Six Paths]] explains that this happened to his mother and [[spoiler:Madara]] when they gained the power of [[spoiler:the God-Tree]]. Not coincidentally, both struck upon the idea of executing an AssimilationPlot where they would effectively become gods [[spoiler:because a servant of Kaguya had deliberately planted information to recreate said plan]].
* ''Franchise/{{Pokemon}}'':
** ''Manga/PokemonAdventures'' uses this in the ''Ruby/Sapphire'' arc. The Red and Blue Orbs can be wielded by mortals to control Groudon and Kyogre, but sufficient willpower is required to prevent loss of self. One Magma Elite tried and was driven mad; Archie and Maxie were so consumed by their lust for power that the Orbs wielded them. [[spoiler:To prevent the same from happening to their (unknowing at the time) new hosts, Juan, Liza, and Tate used the temporal abnormalities of Mirage Island to temper Ruby and Sapphire's collective resolve. Ruby foolishly coaxed the Blue Orb from Sapphire for his own use, but he turned out to have enough strength of will to calm both titans once more.]]
** The ''Anime/{{Pokemon}}'' anime:
*** Oakley loses it in ''Anime/PokemonHeroes'' and tries to destroy the world once she gains control of a machine powered by Latios. Even her partner Annie is startled by the change.
*** Korrina's Lucario is unable to control the power of Mega Evolution, and thus whenever it Mega Evolves it goes insane, though it's training in an attempt to gain control over itself.
* In ''Anime/PuellaMagiMadokaMagica'', almost all magical girls [[spoiler:lose it in varying degrees due to a combination of having awesome power and still not getting what they wanted, having to fight constantly and lose any semblance of a social life, having their souls sucked out and put in a gem, and then finding out that the enemies they've been fighting all this time used to be magical girls themselves]]. Prime examples include [[spoiler:Sayaka, and Mami in another timeline]]. More to the point, [[spoiler:witches are magical girls that have succumbed to despair and insanity]].
* Itsuki's Glam Sight in ''LightNovel/RentalMagica'' gives him his CrouchingMoronHiddenBadass ability that makes him just the right sort of leader for his team of mages. However, the more he uses it, the more it eats away at his sanity. Thus, Honami and the others warn him not to use it as much as possible.
* In ''LightNovel/TheRisingOfTheShieldHero'' the Curse series of the Legendary Weapons tend to provide power boosts and functions not normally available, such as Naofumi's Wrath shield giving him an actual attack. Each Curse is associated with one of the [[SevenDeadlySins sins]] and activating it runs the real risk of the wielder's mind becoming overwhelmed with that sin.
* In ''Manga/RosarioToVampire'', being injected with a youkai's blood gives you all of their abilities for a short while. Eventually, the effect starts wearing your body down. One time too many will kill you (if you're lucky) or [[BodyHorror horribly mangle your body]] and, if vampire blood is involved, leave you a mindless killing machine. Fortunately, there are [[PowerLimiter ways to counteract]] the less-than-desirable effects. Subverted with Tsukune, in the fact that he doesn't even ''have a mind'' anymore when this happens.
* ''[[Anime/SCryEd s-CRY-ed]]'' shows this one off pretty well, with most (if not debatably all) of the Alter Power users being completely insane to some degree. Particular samples include Straight Cougar, most of the one-shot villains, and our main Kazuma (whose personality initially flips between JerkWithAHeartOfGold and nice-guy… only for the nice guy to completely vanish by the final battle). It's worth noting that both Cougar and Kazuma are rare ''heroic'' examples of this trope. They're clearly bonkers, but they're still the good guys.
* Possibly a coincidence, but the three most powerful [[Franchise/SailorMoon Sailor Soldiers]] are the less unhinged:
** Sailor Venus is the most powerful of the 'normal' Sailor Soldiers, a GenkiGirl on steroids and a hell of StepfordSmiler.
** Sailor Moon is one of the two candidates to the title of most powerful of the Sailor Senshi, and her personality is ''extremely'' similar to Sailor Venus ({{justified|Trope}} as she's Venus' {{Expy}}), the main differences being that Venus is a born DramaQueen and LargeHam and Moon's happiness is genuine;
** Sailor Galaxia is the other candidate to the title of most powerful Sailor Senshi (and in the anime she ''is''), and she's an OmnicidalManiac. [[spoiler:Galaxia is a subversion, though. She was perfectly sane and heroic as Sailor Galaxia, fighting on the side of good during the Sailor Wars. It was only after she decided to seal the spirit of Chaos in ''herself'' that she went insane.]]
* In ''Manga/{{Saikano}}'', this more or less happens to [[spoiler:[[WoobieDestroyerOfWorlds Chise]], who loses her sanity as the [[BodyHorror weapon of mass destruction inside her]] grows and apparently slowly takes over her brain, turning her into a [[AxCrazy killing machine]] against her will]]. She gets [[ThePowerOfLove better]]. [[FromBadToWorse But]] [[TheEndOfTheWorldAsWeKnowIt then]] [[DownerEnding again]]...
* In ''Manga/SoulEater'', the characters infected with [[TheCorruption Black Blood]] have their strength increased tremendously when they use it, but also run the risk of losing themselves completely to insanity. Oops.
** The struggle between power and insanity is best depicted with Soul. After he's infected with Black Blood after being struck by Ragnarok, his inner psyche gets a new persona in the form of the Little Red Demon. The Demon represents the Black Blood, and he's either trying to tempt Soul to use its power (which he sometimes does, but for Maka's sake he always vows to do it on ''his'' terms, fighting the madness) or just trying to shove Soul's personality aside and take over.
** Also the result of misusing the Nakatsukasa Purpose, which also drives you mad whilst killing you slowly (it damages your soul).
** This is also the reason why witches are so dangerous in the series. Up till a certain age, they're normal. But then the "Sway of Magic" affects them and causes them to be evil and destructive. However, there are a few exceptions where this doesn't happen due to the witch having their mind on something else other than their magic. In addition, those who possess magic which has little in the way of destructive capabilities are much more resistant, if not outright immune to the Sway: [[spoiler:Kim Dheal, for example, has healing powers and is more or less immune]].
*** [[spoiler:Black☆Star and Death The Kid use it to their advantage.]]
** Several characters use insanity to their advantage, but most do so from [[TheCorruption outside]] sources where they are at risk of permanently losing their minds. Even the Nakatsukasas trace their power back to Arachne's experiments. Kid's is a unique case so far because he is an AnthropomorphicPersonification of a kind of insanity, albeit a deliberately weakened and incomplete one (a 'fragment of Shinigami').
* In ''Manga/TenjhoTenge'', characters who possess supernatural powers are remarked as always being in danger of becoming insane. A classic example of this is Natsume Shin, Maya and Aya's elder brother who was overwhelmed by his powers and started killing random people. This leads to powers being referred to as "Dragons" that will devour their wielder's sanity. Because of this, there is a tremendous social stigma attached to the possession of supernatural abilities, which naturally only serves to aggravate the problem even more.
* ''Manga/TokyoGhoul'' has the [[InstantArmor Kakuja]] form, a rare mutation that results from {{cannibalism|Superpower}}. Considered either an urban legend or a forbidden power, it has a tendency to erode the sanity of the user. [[spoiler: Kaneki]] was already walking a thin line when his incomplete form developed, with him suffering complete mental breakdowns every time he uses it. The other primary Kakuja user of the series, the [[TheDreaded One-Eyed]] [[EvilGenius Owl]], is shown to mentally regress into a giggling lunatic while using its power in sharp contrast to its normally keen mind.
** Urie from the :re sequel undergoes a surgery to remove part of the frame over his kagune in order for it to access a higher power level. When he uses his kagune after this, he becomes out of control and mad with power. He rants about his hatred of others as he viciously attacks and has a mental breakdown.
%%* The cyclone-riders in ''Manga/{{Uzumaki}}''.
* The witches of ''Manhwa/WitchHunter'' are a bag of mixed nuts. The magic powers they wield have different affects on all of them. Some stay the same sweet person they were before, the only change they undergo being the magic they now wield and their now immortal bodies... Others not so much. The main character's sister went completely insane upon gaining her powers, murdered her own father, her brother's beloved mentor, and ''countless'' tens of thousands of people and only approaches her normal mentality as she uses her magic too much and starts running out. Almost ''all'' witches introduced who are not on the side of the humans are sadistic and cruel, viewing human life as something deserving of only destruction, despite all of them having once been human.
* [[StrawNihilist Sensui]] from ''Manga/YuYuHakusho'' would probably count, as he seems to have been at least ''slightly'' cracked before he [[FaceHeelTurn officially]] [[StartOfDarkness went insane on the mission to the Black Black Club]]. (As a child, he says that he is the [[WellIntentionedExtremist "warrior for justice"]]. Wondering why demons only attacked you as opposed to other people, and knowing about the extent of your own power to destroy other living things leads to this trope.)
* Due to [[PhlebotinumBreakdown metatron poisoning]], Radium of the ''VideoGame/ZoneOfTheEnders'' {{O|riginalVideoAnimation}}VA, ''Idolo'', goes completely off the deep end after spending just a moment too long in the cockpit of the Idolo. [[DownerEnding This does not end well for anyone.]] The same can be said for Ridley Nohman with his Anubis, from a rather immoral rebel leader (in ''Dolores, I'') into destruction-obsessed guy (''ZOE: The 2nd Runner'').
[[/folder]]

** Sunset Shimmer in [[WesternAnimation/MyLittlePonyEquestriaGirls2013 the first move]]. After putting on the Element of Magic, she undergoes a PainfulTransformation into a demon, and promptly [[JumpingOffTheSlipperySlope jumps off the slippery slope]], with her goal changing from "get Princess Celestia to acknowledge me" to "conquer Equestria with my brainwashed army". Notably, when she's taken down and reverts to human form, she's ''crying'' in horror about the things she did.
** In ''WesternAnimation/MyLittlePonyEquestriaGirlsFriendshipGames'', [[spoiler:Human Twilight is pressured by Principal Cinch and the others into unleashing the magic from her amulet to help Crystal Prep win the games, which contained all the captured magic from the Humane 6 over the course of the movie. The intense exposure causes her to snap and transform into a evil magical winged demon form called [[SuperpoweredEvilSide Midnight Sparkle]], DrunkWithPower and dead set on opening dangerous portals to Equestria in order to understand magic, at the expense of destroying their world. It takes the combined efforts of Spike and Sunset Shimmer to snap her out of it]].

** ''WesternAnimation/MyLittlePonyEquestriaGirlsMagicalMovieNight'' has [[spoiler: Juniper Montage]] who in the third episode finds a magic mirror that shows her what she desires (to be an adored movie star). After using the mirror to grant her wishes and sucking the main cast inside, the mirror powers up and turns her into a giant version of her movie star self, as well as giving her delusions that the people running and fleeing in terror are all actually just admiring fans. The quick down-slide in her sanity from the second episode (where she just sabotaged a movie) is blamed on the mirror and she is EasilyForgiven, with references to Twilight and Sunset's instances of the trope from above being used as justification.

* ''Franchise/WonderWoman'': This is an issue for gods, and the Greek pantheon actually split themselves in two in antiquity to create the Roman pantheon because the influx of worshipers was too much for them. In modern times they don't worry about it as much since they have far fewer worshipers and they've actually rejoined with their Roman counterparts. Some of the gods have trouble with it anyway, like Ares, Aphrodite and Dionysus because their power doesn't just come from worshipers and their attributes influence their mindset and actions.

* ''ComicBook/WonderWomanOdyssey'': With every unjust death, Nemesis' power grew until she could reign alone above all other Greek dieties, whom all fled to the mortal plan in terror and went into hiding to escape her wrath. It also drove her completely mad.

This trope can also arise if the principle that knowledge is power is extended to TheseAreThingsManWasNotMeantToKnow. If all else fails, it'll seem like it happened just to make [[AnAesop the Aesop]] [[http://en.wikipedia.org/wiki/John_Dalberg-Acton,_1st_Baron_Acton#Catholicism_and_Lord_Acton "Power tends to corrupt, and absolute power corrupts absolutely"]] appear in the story.
KarmicDeath is a frequent end for not only the subject, but the scientists who created him/her/it.

* ''FanFic/YetAgain'' shows that it doesn't even have to be physical power. Hiruzen Sarutobi, the Third Hokage, straight up admits to Naruto that being Hokage for so long drove him insane -- he just managed to channel it into productive and/or harmless/comical ways, as shown with his near-violent hatred of paperwork.

** In [[Recap/DoctorWhoS30E13JourneysEnd "Journey's End"]], the Doctor's companion, Donna Noble, [[spoiler:somehow gains every bit of knowledge and power that the Doctor has.]] The Doctor, unfortunately, is forced to give Donna a complete mind wipe of her entire knowledge of the Doctor/the TARDIS/the entire time she was on the show because [[spoiler:being ''the Doctor Donna'', as the Ood called her,]] will kill her. This circumstance means that the Doctor can never see Donna again, as she will remember everything and die. It's not going insane with power that would kill her, it's that humans are physically unequipped to handle a Time Lord mind. Donna was still physically human but with a Time Lord consciousness, and it was going to literally burn her brain out in very short order, certainly before she had time to go mad with power.

-->'''David Mitchell:''' That's a very, very irresponsible use of power!
-->'''Greg:''' Yeah, well, Lee Mack's not here, this is my bench, and I tell you it's a lie!
-->'''Rob Brydon:''' Why? What about that was unconvincing?
-->'''Greg:''' It's irrelevant, I've made my decision!

* In ''VideoGame/{{Borderlands 2}}'', Gaige suffers from this heavily when using Anarchy. She even lampshades it by going "I'm going mildly insane!"

* In the Bad End of ''VisualNovel/SpiritHunterNG'', [[spoiler:Akira's Bloodmetry becomes so powerful that it starts to deteriorate his physical and mental health. A mysterious voice tries to help out by transforming him into something inhumane - with the new form comes new powers, and the complete degradation of Akira's personality into something primal.]]

* WebVideo/RickPointBlank: The plot revolves around a serum that grants a HealingFactor, makes you evil, and possibly makes you crave cookies and milk.

* In ''Roleplay/RubyQuest'', as the Cure [[LovecraftianSuperpower mutates]] its victims, they become progressively more powerful but also more unhinged.
* Burnscar from ''{{Literature/Worm}}'' becomes more unstable and violent the more she uses her [[PlayingWithFire power]].
** A lot of characters in ''Worm'' fit this trope. Since superpowers can only be gained by going through [[TraumaticSuperpowerAwakening highly traumatic experiences]], most parahumans aren't particularly stable individuals.
** Skitter's trigger event caused her to abruptly gain awareness of millions of insects. The shock of this was so severe it was assumed she'd had a psychotic break and she spent a week in a psych ward. [[spoiler:After having Panacea mess with her brain, she gains the ability to control people but her mind is gradually taken over by her shard.]]
* ''Machinima/RedVsBlue'': The Meta has the abilities and A.I. of every Freelancer it has killed so far. That many A.I. in one body, however, have caused it to be more than slightly snarling mad. To the point where it doesn't seem able to speak itself, only growl. ([[DeadpanSnarker Church]] was naturally ''thrilled'' when he heard this.)
-->'''Church:''' "Oh great, powerful, and crazy. What a winning combo."
** Also in RVB, when Simmons takes power after Sarge's "death" (he wasn't)
-->'''Grif:''' "Simmons, I think you've gone mad with imaginary power."
-->'''Simmons:''' "Oh no, Grif. I've gone mad with very real power."
* Unsurprisingly for such a {{Troperiffic}} series, ''Literature/WhateleyUniverse'' has a number of described - and sometimes treatable - psychological conditions that can result from possessing superpowers. Aside from [[ScienceRelatedMemeticDisorder Deidrick's Syndrome]] (which can affect almost any mutant, but is most common among Devisors and electrical Manifestors), there are [[ComicBook/HarleyQuinn Quinzel]]-[[ComicBook/NormanOsborn Osborn]] Syndrome, which makes the sufferer DrunkOnTheDarkSide; Hercules Syndrome, which causes Exemplars - '''all''' Exemplars - to have difficulty controlling their emotions; and Galahad Syndrome, which causes monomania (often of the ChronicVillainy or ChronicHeroSyndrome varieties), again being a more or less universal tendency in Exemplars.
** Part of the justification used by the [[FantasticRacism hate groups]] Humanity First! and the Knights of Purity is their claim that mutants invariably go off the deep end, making even those with harmless powers too dangerous to allow in society.

** In [[Recap/MyLittlePonyFriendshipIsMagicS3E5MagicDuel "Magic Duel"]], [[RivalTurnedEvil Trixie]]'s sanity deteriorates while under the influence of a magic-boosting ArtifactOfDoom; the first thing she does after banishing Twilight being to turn Ponyville into a micronation with her as its [[TheCaligula Caligula]], then it comes to a head when she has [[ThoseTwoGuys Snips and Snails]] drag her chariot across the ground, as [[AbsurdPhobia she is now so paranoid that she can't trust wheels]].
** In [[Recap/MyLittlePonyFriendshipIsMagicS4E23InspirationManifestation "Inspiration Manifestation"]], the more Rarity uses the book's power, the more deranged she becomes.
** In [[Recap/MyLittlePonyFriendshipIsMagicS9E25TheEndingOfTheEndPart2 "The Ending of the End Part 2"]], Pinkie Pie briefly absorbs Discord's chaos magic and goes mad with her newfound power. Fortunately, Discord promptly drains his magic back out of her.

** The 'return' of Jean Grey in the ''ComicBook/XFactor'' retread of the original X-Men was so badly done that it left ''permanent'' damage to the storylines of the Marvel Universe. The obvious moral cop-out of 'it wasn't really her' not only undid the basic ''point'' of one of the landmark storylines of the MU, but was done in a half-assed way, because they tried to claim that Jean deserved the credit for the self-sacrifice of the Phoenix entity, but not the blame for its crimes, even though both supposedly derive from the human element from Jean. Sorry, folks, you can't have that both ways.

* ''A Fire Upon the Deep'' from Creator/VernorVinge's ''Literature/ZonesOfThought'' {{Trilogy}} has "godshatter", the NeuralImplanting by {{Sufficiently Advanced Alien}}s of a massive ExpositionBeam into a person's brain. It would probably be super helpful if the [[BlessedWithSuck seemingly random jumble of information]] didn't turn the person into an erratic, drooling savant for most of the time.

A.K.A. Comes Great Insanity for short. To go with the original version, ComesGreatResponsibility. Compare TheCorruption, AlmightyIdiot, DrunkWithPower, GodForADay and MadGod.

* ''Fanfic/WhiteSheepRWBY'': Jaune at one point mentions that all powerful huntsmen are insane, mostly in small way but still definitely noticeable. At first his friends have no idea what he's talking about, but as he lists off all the huntsmen he knows, they realize they can't think of a ''single'' counter-example.

*** Oddly enough, Jean and her relatives actually tend to handle vast/cosmic scale power pretty well, Phoenix saga aside. Jean spent most of the 90's and early 2000's being incredibly powerful under her own steam, and her teenage counterpart has largely kept her powers in hand too. Meanwhile, her children, ComicBook/{{Rachel|Summers}}, [[ComicBook/XMan Nate]], and ComicBook/{{Cable}}, are all vastly powerful (in Cable's case in particular, and recently with Nate, intermittently) and entirely sane. Cable seemed to undergo this when his Techno-Organic virus went into remission and he created the floating island of Providence, jacking him up to the point where he could fight the Silver Surfer on even footing, hold Providence in the air, and repair the landscape around them as they fought. As it turned out, however, it was a GenghisGambit to get the world to unite against him. Nate, meanwhile, lived in mortal terror of a combination of this and lethal cosmic scale PowerIncontinence, but largely held it together pretty well - which, for a LivingWeapon who had no functional childhood, grew up in the hell that was the Age of Apocalypse, had to live with the knowledge that he was slowly dying, and had just about everyone trying to manipulate or destroy him once he got to 616, is really quite impressive. As for Rachel, of the lot of them, she's by far the sanest.
*** Then in ''ComicBook/UncannyXMen2018'', Nate appeared to a) regain his powers and then some, b) lose his marbles and declare his [[AGodAmI status as a god/messiah]]. Considering his status as a MessianicArchetype and raw power, it's a bit hard to argue with. However, it's revealed at the end of the arc that [[spoiler: he got his powers back, but at the price that he's dying, again, and he's desperate to do something good with his powers while he can]].

*** Some writers have tried to pull the same thing with Havok (Cyclops' brother), who controls (or at least, has a degree of access to) the Power Cosmic, ''another'' fundamental force of the Marvel universe. This is made apparent with the introduction of [[spoiler:the long-anticipated third Summers brother Vulcan, who has near-Phoenix level command of the Power Cosmic but at the cost of being completely off his rocker]].

* Dark Chips in the ''VideoGame/MegaManBattleNetwork'' series (and its AnimatedAdaptation, ''Anime/MegaManNTWarrior''). [[GameplayAndStorySegregation Gameplay-wise]], however, they're more of a DeadlyUpgrade, increasing your power output but permanently shortening your lifespan.

* An episode of ''WesternAnimation/SamuraiJack'' centers around Jack defeating three shadowy warriors with amazing powers who attack anyone who comes near. After the battle, it turns out that the warriors were actually three men who used a magic well to wish for the power to be the greatest warriors in the land. While the well granted their wish, it also made them blind and took their free wills. And it was All behind this.

* An episode of ''WesternAnimation/SamuraiJack'' centers around Jack defeating three shadowy warriors with amazing powers who attack anyone who comes near. After the battle, it turns out that the warriors were actually three men who used a magic well to wish for the power to be the greatest warriors in the land. While the well granted their wish, it also made them blind and took their free wills.

* SelfDemonstrating/{{Deadpool}} was probably messed up before developing terminal cancer, but the Weapon X program (which initially ''failed'' to give him a HealingFactor) gives him a hard shove in that direction. Then Dr. Killebrew experiments on and tortures him to the point of having visions of (and ''falling in love with'') [[TheGrimReaper Death]]. What finally demolishes his sanity is when Killebrew orders him killed, his healing factor finally kicks in, saving his life, making his disfigurement permanent, and causing Death to reject him. Depending on the writer, he's a mix of AxCrazy, DeadpanSnarker, gleeful GenreSavvy, and MediumAwareness.

* ''VideoGame/FinalFantasyVII'' has its own version; being injected with Jenova cells makes you powerful, but it also leaves you vulnerable to becoming BrainwashedAndCrazy -which is what happened to Sephiroth (though it only started when he learned the truth). And Cloud.

** Interestingly enough, the only person that ''doesn't'' go crazy from Jenova cells is Zack. And we all know how that ended.
*** In addition, once Cloud is able to overcome the Jenova cells in his body, he never goes crazy again.
*** Although it is never specified if the Jenova cells caused Hojo to be brainwashed, his injecting himself with Jenova's cells (with an amount that obviously was a much larger amount than that of a SOLDIER) certainly caused Hojo to become a ''lot'' more crazy.
** To be fair, the Soldier process involved extensive training (I'm assuming there were others around, since it was the Soldier ''Program'' -- known about by the people living under Midgar, at the very least), and, one would assume, psychological testing, well before any infusion of Mako or Jenova cells. Neither Sephiroth nor Cloud had opportunity for this, since the first was injected before he was friggin' born, and the other was just found as a convenient test subject (and we all know how great Hojo's morals are). Zack is the only on-screen Soldier who was created normally.
*** Other Soldiers are shown in ''VideoGame/CrisisCore'', and they, too, are normal. (Genesis and [[spoiler:Angeal]] don't count, since they were in their own experiment.)
*** Why in the first place do you think that there were Soldiers (1st Class at least) who were ''not'' created as an experiment at all?

** Seath the Scaleless, as the only dragon without natural immortality (other dragons have it because of their scales, [[ExactlyWhatItSaysOnTheTin which Seath obviously lacks]]), conducted huge amounts of research trying to gain immortality some other way and more or less invented the entire practice of sorcery in the process. He also drove himself completely insane, to the point that he starts kidnapping people and turning them into bizarre monsters for no particular reason other than [[ForScience because he can]].
** Big Hat Logan, one of the most accomplished human sorcerers in the world, studies Seath's work in the Archives and eventually goes violently insane from the magical study, to the point that he strips naked in an attempt to emulate Seath's lack of scales.
** The Four Kings of New Londo and their followers, the Darkwraiths, have become subsumed by the power of the Abyss and now mindlessly attack any humans they can find, determined to absorb Humanity from them to further increase their power. They act more like animals than humans.
** Manus is one of the most powerful characters in the series, and has incredible power over Dark, and in fact is the being who spawned the Abyss. Notably, he's an accomplished sorceror, a practice that requires a high degree of intelligence. He's also completely stark raving mad, attacking everything around him in a berserk fury. The corrupted citizens of Oolacile act like miniature versions of him: violent, angry, and forever desperate to further increase their power. All of them were ordinary people before they tried to obtain the power of the Dark Soul.

** The third game continues the tradition with Oceiros, whose epithet is "The Consumed King". The guy found Seath's giant library of sorcery knowledge, and, you guessed it, went insane from studying it (and also turned himself into a dragon somehow). When you arrive to fight him, his arms are held as though cradling something, though there's nothing there. His dialogue reveals that he believes he's holding his youngest child, Ocelotte. Partway through the fight he finally realizes his child isn't there, and that's when he [[TurnsRed gets]] ''[[TurnsRed really]]'' [[TurnsRed mad]].

** Prince Lothric was raised to feed the First Flame and become a Lord of Cinder, but his older brother Lorian worried that his frail and sickly body wouldn't be able to handle the Flame's power. So Lorian decided to burn with Lothric, taking the majority of the Flame's power on himself. Unfortunately, while he had the physical fortitude to handle it, his ''mental'' fortitude was not up to snuff, and left him so brain damaged that he can no longer speak or even use his legs.
** Finally, in the Ringed City DLC for the third game, [[spoiler:Slave Knight Gael attempted to take on the most concentrated parts of the Dark Soul that yet exist. It grants him immense power like unto the Lords of old, but it also twists him into an insanely violent knight who simply hungers for ''more'' of the Dark Soul. Unlike most examples, though, Gael knew this would probably happen before he did it, he just didn't see any other possible way to get the blood of the Dark Soul to the Painter]].