History ApocalypseHow / ClassX5

* In the MagicalGirl CrisisCrossover ''Fanfic/ShatteredSkiesTheMorningLights'', [[Anime/SmilePrecure Joker]] unleashes [[NoNameGiven "the entity"]], a colossal [[SpaceTimeEater space-time eating]] EldritchAbomination, upon the Precure multiverse. It causes ''countless'' Class X-5s, consuming every possible future of the first ten Precure series[=/=]continuities, [[RetGone RetGone-ing]] all the ones beyond that[[note]]the ''[[Anime/MahoGirlsPrecure Mahou Tsukai]]'', ''[[Anime/KiraKiraPrecureALaMode A La Mode]]'', and ''[[Anime/HugttoPrettyCure Hugtto]]'' universes are shown being destroyed before the events of their series can even begin, and [[PaintingTheMedium even the]] ''[[PaintingTheMedium text headers]]'' [[PaintingTheMedium for the "facets" after theirs begin cutting off mid-word...]][[/note]], and causing what's left to collapse together into a catastrophic TimeCrash.
* In ''DC/Marvel'' crossover ''Fanfic/TalesOfTheOtherverse'', a piece of the destroyed Green Lantern Central Power Battery weakened the walls separating the Otherverse form other realities. Suddenly, super-villains, dinosaurs, monsters and the like were invading the Otherverse Earth and slaughtering its denizens. To make matters worse, the dimensional walls keep weakening, and their collapse might lead to the collision and destruction of multiple realities.
-->'''Access:''' "And that is where the current problem lies. The Nexus is being destroyed from within. Its walls are buckling, allowing more and more seepage."\\
'''Rogue:''' "Seepage?"\\
'''Mon-El:''' "With the walls weakened, it means that it is easier for entities from other universes to cross over into the Nexus. Seepage."\\
'''Access:''' "Exactly. And it is a portion of the Great Battery that is causing the walls of reality to weaken. Somewhere, in that new universe, on the planet Earth, a malfunctioning fragment of the Battery is acting like a cancer. It's slowly eating away at the Nexus. And if it weakens much more, those walls are going to break."\\
'''Invisible Woman:''' "Not another Amalgam?"\\
'''Mr. Fantastic:''' "Oh no. We wouldn't be so lucky. "Amalgam was the merger of two realities into one. This will be worse. This will be the sudden collision of a multitude of realities striving to occupy the same space and time."\\
'''Dr. Strange:''' "Total, complete destruction."
* In the ''[[Franchise/{{SonictheHedgehog}} Sonic]]/WesternAnimation/{{Amphibia}}'' crossover ''[[https://archiveofourown.org/works/46054189/chapters/115929175 Gems of Calamity]]'', [[WebAnimation/SuperMarioBrosZ Mecha Sonic/Metallix]] successfully kills Sonic and collects all seven Chaos Emeralds, which he uses to embark on a massive rampage throughout Sonic’s home universe - and several parallel universes too, killing all life in them (while outright destroying others). He even managed to break into the Guardian’s dimension and control it for five days before the Calamity Trio intercepted and battled him.

* ''Franchise/TheDarkTower'': This is what happens if the Tower falls: The utter reversion of every single universe, dimension, plane, time, space, etc. to the chaos from whence they came. The BigBad wants this because he claims he will be able to rule that chaos forever afterwards. The worrying part is that this is starting to happen already at the beginning of the series. Even more scary is that the protagonist has to succeed every single time. [[EvilOnlyHasToWinOnce The antagonist just has to win once]]. [[spoiler: However it seems that each time it resets, the Gunslinger gets something that might make this cycle the last one where he has to win.]]
* In Creator/LarryCorreia's ''Literature/TheGrimnoirChronicles'', the Power is being pursued by the Enemy that destroys the universes it attached itself to. Summoners summon the remnants of the survivors of the previous worlds.

* In Creator/LJagiLamplighter's ''Literature/RachelGriffin'' series, universes are being destroyed. The main characters work out that some characters are in fact refugees from them, magically fit into the universe. [[spoiler:Though Rachel is warned that very few people can be rescued when a universe is destroyed.]]
* In ''Literature/RiddleOfTheSevenRealms'' [[spoiler:an ancient demon plots to destroy all known worlds by lighting a fire in his home dimension, which will punch a hole into the void and suck in not only the demon realm, but also all other worlds that connect to it via flames. (Presumably, any undiscovered universes that lack the "flame permeates all" rule of wizardry would escape this fate, making it this level and not Class Z.)]]

* In ''Series/Dark2017'', [[spoiler:This is the fate of both Adam and Eve's universes after the StableTimeLoop is broken.]]
* This turns out to be the big twist in ''Series/Loki2021'': [[spoiler:There was a multiversal GreatOffscreenWar going on before the events of the Franchise/MarvelCinematicUniverse, reportedly involving all variations of ComicBook/KangTheConqueror, and the last survivor, going by the name He Who Remains, created the [[TimePolice Time Variance Authority]] to prune any and all deviations of the Sacred Timeline from being created so that another, possibly more crueler Kang, isn't created. This gets undone when the Loki variant known as Sylvie kills He Who Remains, causing the Sacred Timeline to erupt into many timelines.]]

[[folder:Web Original]]

* ''WesternAnimation/{{Futurama}}'': In one WhatIf scenario, Fry destroys almost all reality, leaving himself, UsefulNotes/AlGore, Creator/StephenHawking, [[Series/StarTrekTheOriginalSeries Nichelle Nicols]], and Creator/GaryGygax to play ''TabletopGame/DungeonsAndDragons'' for the rest of eternity.
* In ''WesternAnimation/JusticeLeagueCrisisOnTwoEarths'', after discovering the existence of the multiverse, [[StrawNihilist Owlman]] decides to detonate a world-destroying bomb on [[TheEarthPrimeTheory Earth Prime]] to cause a chain reaction that would erase the entire multiverse. Batman stops him by sending him and the bomb to another alternate Earth that was a frozen wasteland.
* The [[AdaptationalVillainy snake]] from the animated adaptation of ''Literature/TheLittlePrince'' has, as established in the setting, existed before the known universes. Being annoyed by the new presence his goal became to destroy all of the known universes there are, with only him still existing. Later on however he would fall in love with a rose that he would want to keep for himself. He would however still wipe out everything else.

* Similarly, in ''WesternAnimation/TurtlesForever'' Utrom Shredder destroys his native dimension and begins destroying another, eventually wiping out every universe that contains the Teenage Mutant Ninja Turtles.
* Comes ''very close'' in ''WesternAnimation/WhatIf2021'', due to [[spoiler:Infinity Ultron discovering the Infinity Stones and the existence of alien life, causing him to kill almost ''all'' the universe[[note]]excluding Black Widow, who is transported to another universe as a reward for saving the multiverse[[/note]], then discovering Uatu's presence and the greater multiverse, revising his goal to continue his genocidal activities across it, and succeeds in wiping out several universes before being defeated.]]