History Main / ResidualEvilEntity

* ''WesternAnimation/SamuraiJack'': At some point in the very ancient past, an unnamed primordial entity of immense power and malevolence attempted to consume the universe. It was destroyed by the gods Odin, Ra, and Rama before it could do so, but a single sliver of this entity escaped and crash-landed on Earth, where it eventually gained sapience and became the series' main villain, the demon Aku.

Compare EvilPowerVacuum. Not to be confused with ''Franchise/ResidentEvil''. Sometimes related to YouKillItYouBoughtIt, when killing the EvilOverlord turns the person into the ''new'' one.

* ''WesternAnimation/WorldOfQuest'': The episode "Mirror Quest" has Quest being split into a good and evil version of himself. The evil Quest goes on to defeat Spite and his henchmen and becomes the new leader of Spite's army, with the heroes trying to find a way to stop him. Fortunately, the good Quest manages to apprehend his evil self long enough for Anna to merge them back into the original Quest.

* ''WesternAnimation/JohnnyTest'': In "The Good, the Bad & the Johnny", Susan and Mary decide to remove Johnny's bad gene in order to make him nicer. Unfortunately, events lead to the extracted bad gene growing and gaining a life of its own, resulting in a Johnny that is 100% bad that runs around Porkbelly pulling increasingly dangerous pranks. The girls and Dukey manage to capture the bad Johnny and merge it and the good Johnny back into one, with Susan and Mary learning to accept all parts of their brother and Johnny learning to try and be a better person.

* ''WesternAnimation/JohnnyTest'': In "The Good, the Bad & the Johnny", Susan and Mary decide to remove Johnny's bad gene in order to make him nicer. Unfortunately, events lead to the extracted bad gene growing and gaining a life of its own, resulting in a Johnny that was 100% bad which ran around Porkbelly causing increasing dangerous pranks. The girls and Dukey manage to capture the bad Johnny and merge it and the good Johnny back into one, with Susan and Mary learning to accept all parts of their brother and Johnny learning to try and be a better person.

* ''WesternAnimation/JohnnyTest'': In "The Good, the Bad & the Johnny", Susan and Mary decide to remove Johnny's bad genes in order to make him nicer. Unfortunately, events lead to the extracted bad genes obtaining a life of its own, causing there to be one bad Johnny and one good Johnny running around Porkbelly. The girls and Dukey manage to capture both halves and merge them back into one Johnny, with Susan and Mary learning to accept all parts of their brother and Johnny learning to try and be a better person.

In some cases, [[EnemyWithout it forms a mind and/or body of its own]]. In others, it joins some [[UltimateEvil greater entity]] which will exist AsLongAsThereIsEvil. If it's ''particularly'' strong or embedded in a person or the world, it may be impossible to get rid of entirely and fester like a boil ready to burst at the slightest MomentOfWeakness. In some cases, the entity created may not be MadeOfEvil itself but was nonetheless created by the prior act of purification.

* ''WesternAnmation/WorldOfQuest'': The episode "Mirror Quest" has Quest being split into a good and evil version of himself. The evil Quest goes on to defeat Spite and his henchmen and becomes the new leader of Spite's army, with the heroes trying to find a way to stop him. Fortunately, the good Quest manages to apprehend his evil self long enough for Anna to merge them back into the original Quest.

* ''ComicBook/TheInfinityCrusade'': In the third part of the trilogy, it's revealed that Warlock also created a "good" side named Goddess, who is actually just as dangerous and troublesome as Magus, as her definition of good is [[TheEvilsOfFreeWill "eliminate free will"]].
* ''ComicBook/TheInfinityWar'': It is revealed that in the [[ComicBook/TheInfinityGauntlet previous storyline]], Adam Warlock subconsciously used the Infinity Gauntlet to purge the evil from his soul. That evil had since manifested as a purple-skinned EvilDoppelganger of him named Magus.

In some cases, [[EnemyWithout it forms a mind and/or body of its own]]. In others, it joins some [[UltimateEvil greater entity]] which will exist AsLongAsThereIsEvil. If it's ''particularly'' strong or embedded in a person or the world, it may be impossible to get rid of entirely and fester like a boil ready to burst at the slightest MomentOfWeakness. In some cases, the entity created may not be MadeOfEvil itself, but was nonetheless created by the prior act of purification.

This plot element typically leans towards the cynical end of SlidingScaleOfIdealismVsCynicism, at its worst arguing that no problem can ever truly be "fixed" or "settled" and that no person can ever truly be "redeemed". It's also greatly related to the idea of BalanceBetweenGoodAndEvil, because it argues that every victory good has against evil makes evil come back stronger or in some unpredictable form. Which, may also imply that good versus evil is a dance of equal-but-opposite reactions.

Depending on how a work or audience looks at it, this plot point could either discourage complacent behavior by emphasizing that heroes must be ever vigilant, or ''encourage'' such complacency by convincing them that sometimes it's better to do nothing at all. Sometimes, the problem isn't that evil was purged, per se, but the methods the heroic characters used to do so, which may have been flawed, too easy, or both.

** The unnamed Namek that traveled to Earth and studied under the previous God (Kami) of the planet was unable to attain the position himself until he purged himself of evil. He did this by diffusing himself into two entities: one pure good and the other pure evil. His pure evil side, now dubbed Demon King Piccolo, was later [[SealedEvilInACan sealed away]] to prevent him from terrorizing the world, and he escapes during the events of the series. Over the course of the manga, it requires Piccolo dying, being reincarnated, adopting his own pupil, sacrificing his own life and being wished back, and becoming a friends with the protagonists to suppress his evil side enough for him to merge back with his other half to form a whole, benevolent Piccolo. And even then, there's a tiny amount of evil that he must keep suppressed.

* ''Literature/TheStand'': Randall Flagg, the dark man, vanishes in the nuclear destruction of Las Vegas, ending his fledgeling evil empire... until he wakes up on an island surrounded by natives, introducing himself as Russell Faraday and claiming he's come to [[HereWeGoAgain teach them how to be civilized]].

** In Shinto creation myth, the god Izanagi returned from the underworld after a failed attempt to [[OrpheanRescue rescue his deceased wife]] Izanami and cleansed himself. The gods born from this, Amaterasu, Tsukiyomi and Susanoo were not ''evil'' per se, but are decidedly three of the most powerful and influential in all of Shinto belief.
** In general, physical and spirtual impurities are called "kegare". In Shinto doctrine, they must be washed and/or purified through specific rituals called misogi and harae. There are also many Japanese {{yokai}}, or spirits, which are cast-offs or byproduct of other oddities which may not have been dealt with properly or at all.

* Zemus, the evil puppetmaster behind the events of ''VideoGame/FinalFantasyIV'', willingly allows himself to be destroyed just before the FinalBattle. Out from his corpse comes Zeromus, an incarnation of his hatred far more powerful and dangerous that the sorcerer himself could ever be.

* ''Franchise/KingdomHearts'': This is more or less what defines the Heartless, Nobodies and Unversed. The games are not explicitly clear about it, but it's known that if a person "loses heart" or has darkness consume them involuntarily, it turns them into a Heartless. The part of them that's left over without the heart form a Nobody, and Unversed are also somehow connected to despair and negative emotions. Even if someone who lost their heart and became a Heartless regains it (as is the case with Sora), the Nobody they created will still exist.

* ''WesternAnimation/SamuraiJack'': At some point in the very ancient past, an unnamed primordial entity of immense power and malevolence attempted to consume the universe. It was destroyed by the gods Odin, Ra and Rama before it could do so, but a single sliver of this entity escaped and crash-landed on Earth, where it eventually gained sapience and became the series' main villain, the demon Aku.

* ''Series/PowerRangersBeastMorphers'': It's revealed that [[spoiler:Evox is actually Venjix, the BigBad of ''Series/PowerRangersRPM'', being reborn. At the end of ''RPM'', Venjix hid within one of the RPM Rangers' morphers and was acquired by Gird Battleforce, allowing him to be reborn as Evox.]]

* ''ComicBook/TheInfinityCrusade'': In the third part of the trilogy, it's revealed that Warlock also created a "good" side named Goddess, who is actually just as dangerous and troublesome as Magus, as her definition of good is [[TheEvilsOfFreeWill "eliminate free will"]].

* In ''Videogame/TalesOfZestiria'' and ''Videogame/TalesOfBerseria'', Malevolence is capable corrupting any living being that comes in contact with it. The major revelation of ''Berseria'' is that [[spoiler:"malevolence" is born from the darkness in every negative emotion felt within the human heart.]] In ''Zestiria'', is the Shepherd's job to purify the malevolence from its victims. However, even the Shepherds themselves are not immune to its corruption. [[spoiler:This all stems from a [[FixingTheGame curse]] made by the [[GreaterScopeVillain Original Seraphim]] in the hopes of proving its fellow Seraphim that humans and Seraphim can't coexist.]]

* In ''Videogame/TalesOfZestiria'' and ''Videogame/TalesOfBerseria'', There is this evil substance called "Malevolence". It has the ability of corrupting any living being that comes in contact with it. This "malevolence" is born from the darkness in humanity's hearts as every negative emotion has the potential to spawn malevolence. It is the Shepherd's job to purify the malevolence from its victims, however, it is humans that create the malevolence (unintentionally), and even the Shepherds themselves are not immune to the corruption of it. [[spoiler: This all stems from a [[FixingTheGame curse]] made by the [[GreaterScopeVillain Original Seraphim]] in the hopes of proving to the Seraphim that descended to earth that both humans and Seraphim couldn't coexist.]]

* ''Videogame/TalesOfZesteria'': In the game, there is this evil substance called "Malevolence". It has the ability of corrupting any living being that comes in contact with it. This "malevolence" is born from the darkness in humanity's hearts as every negative emotion has the potential to spawn malevolence. It is the Shepherd's job to purify the malevolence from its victims, however, it is humans that create the malevolence (unintentionally), and even the Shepherds themselves are not immune to the corruption of it. In the [[Videogame/TalesOfBerseria prequel]], it is believed that to truly purge the world of malevolence, people must be stripped of their emotions.

** ''Anime/DigimonFrontier'': In the penultimate battle, the Digidestined battle Lucemon, TheDragon of the series. When he is defeated, the Digidestined absorb his Digicode/Fractal Code, but only the light half. The dark half, now unfettered by the light, [[FromBadToWorse grows and forms into the purely-evil Lucemon Shadowlord Mode.]]

!!Examples

[[folder:Film]]

[[folder: Mythology and Religion]]

[[folder: Tabletop Games]]
* Advanced ''TabletopGame/DungeonsAndDragons'' module I10 ''Ravenloft II: The House on Gryphon Hill''. The Alchemist, AKA Count Strahd von Zarovich, creates a device that extracts all of the evil in him and sends it to another plane of existence. The evil becomes a monster known as the Creature, which returns and plagues the Alchemist.

[[folder: Western Animation]]

* After being cowed into submission by Amelia and defeated, ''Film/TheBabadook'' [[spoiler:does not die or go away but instead takes up residence in her basement where it remains weakened and subsisting on worms. Given that the creature is a manifestation of Amelia's depression and grief, which can be controlled and lived with but never truly vanquished]], this makes all kinds of sense.

* A theory about the origin of the energy monster featured in the ''Literature/DoctorWhoNewAdventures'' book ''Nightshade'' is that it's all what's left of a race the First Doctor defeated in the ''Literature/DoctorWhoMissingAdventures'' book ''Venusian Lullaby''.

[[folder:Live Action TV]]
* ''Series/PowerRangersBeastMorphers'': [[spoiler:It is revealed that Evox is actually Venjix, the BigBad of ''Series/PowerRangersRPM'', being reborn. At the end of ''RPM'', Venjix hid within one of the RPM Rangers' morphers and was acquired by Gird Battleforce, allowing him to be reborn as Evox.]]
* ''Series/StarTrekTheNextGeneration'' episode "Skin of Evil". On an uninhabited planet, the Enterprise crew encounters Armus, a being that looks like an oil slick. It says that it is the result of a process that the original inhabitants of the planet used to shed all of their negative traits. It acts in a capriciously evil way, including murdering Tasha Yar.

* ''WesternAnimation/TheFairlyOddParents'': In "Vicky Loses Her Icky", Timmy wishes [[BabysitterFromHell Vicky]] would be nice, and her evil is released as a bug that begins to search for a new host. Eventually, the bug tries to take control of the United States President to use his resources to destroy the planet and [[StatusQuoIsGod Vicky lets the bug possess her again to prevent this outcome]].

* ''WesternAnimation/MyLittlePonyFriendshipIsMagic'', [[Recap/MyLittlePonyFriendshipIsMagicS4E3CastleManeia Castle Mane-ia]] some of the Mane Six are discussing the Pony Of Shadows, a sort of leftover of evil energy that got left behind when Nightmare Moon was defeated. It turns out to be a case of EpilepticTrees, as, while we do see a glowing-eyed shadow in pony shape lurking in the castle at the end of the episode, the concept of the Pony Of Shadows is later retooled in the Season 7 finale to be an EldritchAbomination that was SealedEvilInACan during the prior episode.

** In ''"Citizen Ghost"'', Peter stores the uniforms soaked in Gozer's psychokinetic marshmallow fluff next to the Containment Unit, which still has a leak in it. The leaking ectoplasm combines with the residual energy in the uniforms and the psychic imprints left by their wearers, i.e. The Ghostbusters, to create spectral versions of the team.

[[/folder]]

* ''Videogame/FinalFantasyXIV'': Light and Darkness exist in a cosmic balance where neither can ever truly be "destroyed", but defeating or vanquishing a vessel for either will cause the force that possessed it to go somewhere else, and often reach critical mass where it threatens to become more dangerous than ever. This, for example, is the main problem with defeating Lightwardens; whenever one is defeated, the light inside it has to go ''somewhere'', and the most convenient host is usually [[YouKillItYouBoughtIt the being that defeated it]]. Those that possess the Echo are seemingly immune to this. [[spoiler:But really, they're merely more ''resilient''. After defeating several Lightwardens, the [[PlayerCharacter Warrior of Darkness]] starts being overwhelmed by the light energy entering their body, threatening to turn them into an apocalyptic ''Super''-Warden. The {{Precursors}} that inhabited the star long before recorded history possessed such powerful mana and magical abilities that containing it would have been easy for them, and the BigBad, Emet-Selch, wants to see if the Warrior can handle it to see if mortals are worthy of existence. When they fail, he is disappointed, and [[YouHaveOutlivedYourUsefulness decides to let them succumb]], although his plan later fails.]]

[[folder:Videogames]]

* ''WesternAnimation/MyLittlePonyFriendshipIsMagic'', [[https://tvtropes.org/pmwiki/pmwiki.php/Recap/MyLittlePonyFriendshipIsMagicS4E3CastleManeia Castle Mane-ia]] some of the Mane Six are discussing the Pony Of Shadows, a sort of leftover of evil energy that got left behind when Nightmare Moon was defeated. It turns out to be a case of EpilepticTrees, as, while we do see a glowing-eyed shadow in pony shape lurking in the castle at the end of the episode, the concept of the Pony Of Shadows is later retooled in the Season 7 finale to be an EldritchAbomination that was SealedEvilInACan during the prior episode.