History NoOntologicalInertia / WesternAnimation

*** ''WesternAnimation/RescueAtMidnightCastle'': When Tirac dies all of his magic is undone. The skies turn clear and sunny, the castle turns into a tree-covered hill, and his guards and monsters turn back into the birds and butterflies they used to be.

* ''WesternAnimation/Castlevania2017'': A monster called the Stone-Eye Cyclops lurks in the catacombs under the city of Gresit, [[TakenForGranite turning anyone who it comes across to stone]] so it can [[EmotionEater feed on their terror]] as they're left [[AndIMustScream trapped and fully conscious in their bodies]]. Because the Cyclops is using its magic to ''keep'' its victims trapped in stone, killing it undoes the spell and frees its victims. Unfortunately, it only restores the body as they currently are. [[LiterallyShatteredLives If the statue happened to be broken before...]]
* Happens more than once in WesternAnimation/ConanTheAdventurer, to the point where one character is bewildered when this trope DOESN'T work.

* ''WesternAnimation/TheFairlyOddParents'': In "Whishy Washy", Cosmo and Wanda turn into teenagers [[RetGone thereby getting rid of their child, Poof]], yet the result of a wish they grant beforethen remains, as does Timmy's [[RippleEffectProofMemory memory of Poof]].
** In "Mooooving Day", those who drank the milk don't remember anything they said or did after Timmy releases them from the mind control and restores Dimmadome Acres back to its former state with the Mega Fizzy Juice.
** Surprisingly subverted in the "Timmy's Secret Wish" special; Foop, wanting Timmy to lose ForTheEvulz, provided the final example that sealed Timmy's guilty verdict, which resulted in his faries being revoked and any wish, or product resulting from one, disappearing to an isolated island. However, Foop didn't realize that since Timmy wished for Poof, and an anti-fairy can't exist if the regular one doesn't, that would mean ''he would disappear too.'' In short, in not thinking about the results of the trial and just wanting Timmy to suffer, Foop ended up HoistByHisOwnPetard.

* ''WesternAnimation/TheFairlyOddParents'': In "Whishy Washy", Cosmo and Wanda turn into teenagers [[RetGone thereby getting rid of their child, Poof]], yet the result of a wish they grant before then remains, as does Timmy's [[RippleEffectProofMemory memory of Poof]].

* ''Franchise/{{Ghostbusters}}'': A recurring element in ''WesternAnimation/TheRealGhostbusters'' and ''WesternAnimation/ExtremeGhostbusters'' is that any damages done by the [[MonsterOfTheWeek Ghost of the Week]] is reverted after the ghost is caught or defeated.

* Part of why Gang leaves Crystal Cove at the end of ''WesternAnimation/ScoobyDooMysteryIncorporated''. After they destroy the Evil Entity that has manipulated everyone for hundreds of years, everything it ever did was erased from history. All of the cases and all of the monsters are now gone. Furthermore, this means everyone that the Evil Entity's curse would've corrupted got to live happy, healthy and productive lives (especially the gang's families); the entire scenario weighs heavily on them since they were five of the only six or so people on the planet [[RippleEffectProofMemory who still remember the original timeline]]. As for the other person, it turns out to be ''Harlan Ellison'' of all people (who is able to remember multiple timelines due to being a "genius") and has become the new Mr. E. He's invited them to study at the new university he is at and will grant them plenty of new mysteries to solve.

*** The fact that this trope is averted without the use of Ladybug's Lucky Charm is PlayedForDrama in the New York special, where it's revealed that the Lucky Charm can only fix the damage related to a specific villain or situation; when Ladybug and Cat Noir are unable to save paris from a sentimonster because they were both away at the time, the damage caused is permanent, and they were lucky that it wasn't as serious as it could have been. Also, in season 5, [[spoiler:Cat Noir ends up using his Cataclysm on Monarch, and is horrified at having done so despite him being a villain, especially since it can't be undone without Ladybug's Lucky Charm, which Monarch escaped with (and presumably disappeared when she de-transformed)]].

** Sort-of subverted in an early episode, when Demona cast a spell on Goliath, transforming him into [[{{Brainwashed}} her thrall]] as long as she carried the original spell (or at least, the page from the book it was written in). While the book and the page that the spell was written upon were both recovered and Demona defeated, none of the gargoyles had the necessary magical skill to undo the spell, thus leaving Goliath stuck as a slave to whoever held the spell [[AndIMustScream and fully aware of his actions and unable to stop himself]]. Elisa, however, came up with an elegant solution; she held the page with the spell written on it in her hands and commanded Goliath [[ExactWords to live the rest of his life as if he'd never been put under that spell in the first place]]. Needless to say, it worked.

* ''WesternAnimation/TheAdventuresOfJimmyNeutronBoyGenius'' once had an episode where Jimmy used his Hypno-beam to make his parents think that the next day was his birthday in order to get a chemistry set... instead, the Hypno-beam's power makes them think that ''everyday'' is his birthday. After eventually getting sick of it, Jimmy decides to unhypnotize them, only for the party clown to take the Hypno-beam and accidentally destroy it in a misperformed party trick. The next day his parents tell him that (assumably because he's had so many birthdays) that he's now 18 and going to college, but they were just faking it and destroying the Hypno-beam ''really'' made the hypnosis end (the bill for the clown was still there, though).

** "Conquer": Meteora, [[spoiler: formerly known as Miss Heinous]], has been rampaging through Mewni, shooting people with her newfound laser eye powers [[YourSoulIsMine that take people's souls]], leaving them in a lifeless state with black eyes, with her growing bigger every time she does so. Seeing this happen before at the hands of [[spoiler: Toffee]], Star tries to get to the sanctuary where there is a substance that can revive everyone it's happened to, but fails. In the end, after Meteroa is [[spoiler: turned into a baby]], everyone's souls are automatically restored and they revive, saving Star from having to make ''loads'' of trips there.

** Subverted at the end of the "Diamond Days" arc. Steven [[spoiler: successfully convinces White Diamond to join her "sisters" Blue and Yellow -- plus Steven himself, who carries Pink Diamond's Gem--in healing all of the [[BrainwashedAndCrazy corrupted]] Gems on Earth. By combining their powers, they're able to permanently restore the Gems to their pre-monstrous forms... however, most of those Gems were corrupted for thousands of years, and they retain qualities of their beast forms even after being brought back to their original selves.]]

* In ''WesternAnimation/SupermanTheAnimatedSeries'', this is true with Mister Mxyzptlk's powers. When he's banished back to his home dimension, everything he did is instantly undone; most notably, victims of ForcedTransformation are restored to human form. (Although Lois, who he turned into a horse, still wants to eat the carrot he was feeding her, and questions why when she notices.)

* Happens more than once in WesternAnimation/ConanTheAdventurer, to the point where one character is bewildered when this trope DOESN'T work.

* ''WesternAnimation/PhineasAndFerb'': In the episode "Just Our Luck", Doofenshmirtz invents a "Stinkelkrampen-Inator" which reverses types of lucks each person has, and intended to use it on Roger; it hits Candace who becomes extremely lucky, and it hits the kids who experience misfortune for their Big Idea. Once the inator is destroyed, it causes all the lucks to be reversed back to the way they were before.

** In "The First Day", the majority of students and teachers at Hexside [[MagicEater get their magic eaten]] by a [[BasiliskAndCockatrice basilisk]] who was posing as a school inspector, causing them to pass out. After Luz and the detention students defeat the basilisk, it somehow disspels the eaten magic and it returns to everyone.

* At the end of ''WesternAnimation/The13GhostsOfScoobyDoo'' episode "Ship of Ghouls", when the MonsterOfTheWeek, in the guise of a ship's captain, is returned to the Chest of Demons, the ship itself disappears.

* ''WesternAnimation/StarTrekLowerDecks'': In "[[Recap/StarTrekLowerDecksS1E04MoistVessel Moist Vessel]]", the terraforming fluid tears through the ''Cerritos'', creating all sorts of messes both in the corridors and on the hull. Once Mariner and Freeman {{Technobabble}} up a solution, all the growths revert to orange dust with nary a sign of ship damage. (This includes O'Connor's injuries from having a huge rock fall on him.) Averted with the ''Merced'', which is beyond saving and has to be abandoned.

* Averted in the episode "Marco Jr." of ''WesternAnimation/StarVsTheForcesOfEvil''. Destroying a painting that was causing Marco's body to transform doesn't stop the process, as the ash that the painting became still has the magic enchantment on it. Star and his parents find themselves [[ItMakesSenseInContext having to take a personality test for him]] in order to overwrite the spell instead.
** Played a bit straighter in "Conquer." Meteora, [[spoiler: formerly known as Miss Heinous]], has been rampaging through Mewni, shooting people with her newfound laser eye powers [[YourSoulIsMine that take people's souls]], leaving them in a lifeless state with black eyes, with her growing bigger every time she does so. Seeing this happen before at the hands of [[spoiler: Toffee]], Star tries to get to the sanctuary where there is a substance that can revive everyone it's happened to, but fails. In the end, after Meteroa is [[spoiler: turned into a baby]], everyone's souls are automatically restored and they revive, saving Star from having to make ''loads'' of trips there.

** In "Onion Trade", [[EnfantTerrible Onion]] uses a [[MatterReplicator Replicator Wand]] to flood the entire town in millions of cheap plastic toys, and then replicates cars to throw at the Gems. When they finally get the Wand back [[BlackBossLady Garnet]] destroys it, causing all the duplicates to disappear.

** Subverted at the end of the "Diamond Days" arc. Steven [[spoiler: successfully convinces White Diamond to join her "sisters" Blue and Yellow--plus Steven himself, who carries Pink Diamond's Gem--in healing all of the [[BrainwashedAndCrazy corrupted]] Gems on Earth. By combining their powers, they're able to permanently restore the Gems to their pre-monstrous forms...however, most of those Gems were corrupted for thousands of years, and they retain qualities of their beast forms even after being brought back to their original selves.]]

* [[AvertedTrope Averted]] in the ''WesternAnimation/MiraculousLadybug'' episode "The Collector" - [[BigBad Hawk Moth]]'s plan specifically relies on an akuma sticking around to carry out his orders after he [[spoiler:temporarily renounces his Miraculous, because he plans to akumatize ''himself'' to throw Ladybug off his trail, and [[NoSelfBuffs akumas won't work on the Butterfly Miraculous's owner]]]].
** While "The Collector" has one instance of trope aversion, every single episode of Ladybug other than the first episode of her two-part Origin Story plays the trope more or less straight, as all the damage caused by the super villain of the week OR Ladybug and Cat Noir is undone when she tosses her Lucky Charm in the air.
** Basically Ladybug using her compact to DestroyTheVillainsWeapon is what causes the villain to de-akumize back into their true form of the human that was possessed in the first place, leaving them of no memory of what has happened up to that point.
** However that's specifically Ladybug's power to restore everything. Most of the time even after the Akuma is reverted and purified the effects of their power still sticks, until Ladybug uses her restoration power. The one major exception is [[spoiler:Scarlet Moth in the season 2 finale. When his weapon (which was boosted to allow him to create infinite Akumas instead of just one) is broken, all the Akumas are instantly purified as well as anyone affected by their abilities like Darkblade's enslaved knights, even though this usually requires Ladybug to personally fix]]. Another exception happens in "Félix" when the heroes are fighting Lady [=WiFi=], Princess Fragrance, and Reflekta - Princess Fragrance gets turned into a Reflekta clone during the fight, but doesn't stay that way when the trio are de-akumatized.

* In ''WesternAnimation/SupermanTheAnimatedSeries'', this is true with Mister Mxyzptlk's powers. When he's banished back to his home dimension, everything he did is instantly undone; most notably, victims of BalefulPolymorph are restored to human form. (Although Lois, who he turned into a horse, still wants to eat the carrot he was feeding her, and questions why when she notices.)

*** In ''[[WesternAnimation/MyLittlePonyTVSpecials Rescue at Midnight Castle]]'', when Tirac dies all of his magic is undone. The skies turn clear and sunny, the castle turns into a tree-covered hill, and his guards and monsters turn back into the birds and butterflies they used to be.
*** In "[[Recap/MyLittlePonyAndFriendsE34TheMagicCoins4 The Magic Coins, Part 4]]", Ponyland has been reduced to a lifeless desert, but all it takes is a little rain for it to become green and full of plant life again right in the next scene, which can't take place that much later since the visitors to Paradise Estate are all still there.
*** In "[[Recap/MyLittlePonyAndFriendsE44CrunchTheRockdog2 Crunch the Rockdog, Part 2]]", when Crunch is depowered, everything he petrified is instantly returned to its original form.
*** In "[[Recap/MyLittlePonyAndFriendsE62Somnambula2 Somnambula, Part 2]]", after the crystal that Somnambula relies on for her powers is broken, her victims return to physical youth, her creations vanish as if they'd never been and [[NoImmortalInertia she instantly loses her stolen youth and returns to being an old crone]].

*** In "[[Recap/MyLittlePonyFriendshipIsMagicS2E10SecretOfMyExcess Secret of My Excess]]", Spike's greed causes him to grow into a larger dragon progressively over the course of the episode, until by the end he is a rampaging dragon the size of a small mountain. When he realizes that he was wrong to be so greedy, Spike immediately, and magically, poofs back to his original size.

** In the same episode, almost everyone who is affected by the draining spell passes out or is significantly weakened, but after [[spoiler:the Collector]] puts a stop to it, everyone seems to be fine, although we don't see the Coven Heads recover, and also don't know if their magic has returned or not.

** However that's specifically Ladybug's power to restore everything. Most of the time even after the Akuma is reverted and purified the effects of their power still sticks, until Ladybug uses her restoration power. The one major exception is [[spoiler:Scarlet Moth in the season 2 finale. When his weapon (which was boosted to allow him to create infinite Akumas instead of just one) is broken, all the Akumas are instantly purified as well as anyone affected by their abilities like Darkblade's enslaved knights, even though this usually requires Ladybug to personally fix]]. Another exception happens in "Felix" when the heroes are fighting Lady [=WiFi=], Princess Fragrance, and Reflekta - Princess Fragrance gets turned into a Reflekta clone during the fight, but doesn't stay that way when the trio are de-akumatized.