History CerebusRetcon / MarvelUniverse

* ComicBook/BuckyBarnes, ComicBook/CaptainAmerica's KidSidekick during TheForties, underwent this when brought back by Creator/EdBrubaker. The original version of his origin was that he was a cheery fanboy of Cap who accidentally discovered his secret identity and thus was recruited as his partner to keep the truth from getting out. Then Bucky died in a plane explosion and after that putting kids in harm's way looked like a less appealing idea for Marvel. ''ComicBook/CaptainAmericaWinterSoldier'' then retconned his first origin as propaganda, with the truth being that Bucky was an orphan who grew up [[MilitaryBrat on a military base most of his life]] and when partnered with Steve was essentially a teenage assassin, intended to do the black ops work Captain America couldn't be seen doing. So Bucky went from kid sidekick to {{Child Soldier|s}} [[spoiler:and then to AntiHero when he was brought back as Winter Soldier.]]

** In ''Film/{{The Avengers|2012}}'', Tony's flight through the Chitauri wormhole at the climax of the movie is just a good old fashioned fist-pumping action climax, and his resultant brush with death [[LikeYouWouldReallyDoIt (which he obviously survives)]] is PlayedForLaughs, with Tony absentmindedly rambling about going to get shawarma immediately upon waking up. But then ''Film/IronMan3'' reveals that he actually got PTSD from the experience, and a minor plot point in the film involves him struggling to cope with anxiety attacks following the battle in New York.
*** Furthermore, his brief foray into outer space, as well as seeing the gargantuan Chitauri army there, instils in him the conviction that the biggest threats to Earth are those from alien invaders. His quest to preemptively combat these threats results in him creating [[Film/AvengersAgeOfUltron Ultron]].
** Senator Stern from ''Film/IronMan2'' was more of a comedic pain-in-the-ass than an actual threat, and his attempts to confiscate Tony's armor never really panned out. Then in ''Film/CaptainAmericaTheWinterSoldier'', we find out [[spoiler:Stern is a high-ranking agent of HYDRA, and was likely trying to take Stark's armor so that the organization could mass-produce their own versions.]]
*** Similarly, the World Security Council played CommanderContrarian in ''The Avengers'', pushing Fury to use Tesseract weaponry instead of trying to assemble a RagtagBunchOfMisfits. The councilman leading this charge later returned in ''Series/AgentsOfSHIELD'' as, like Senator Stern, a [[spoiler:leading member of HYDRA, adding context to why he wanted high-powered weaponry so badly.]]
*** And let us not forget the Council's directive to "contain the invasion" by '''dropping a nuke on New York'''...
** This is the whole point of the Sokovia Accords plot in ''Film/CaptainAmericaCivilWar''. It's shown that the Avengers' heroic deeds in the past movies have caused untold amounts of collateral damage, and the main villain of the movie [[spoiler:is a man whose wife and son were crushed to death by falling buildings during the final battle in ''Film/AvengersAgeOfUltron''.]] To hammer this point home, footage of the Hulk fighting the Chitauri from ''Film/{{The Avengers|2012}}'' is shown, and it's revealed that he accidentally knocked debris onto a crowd of screaming civilians. To make it worse, ''Age of Ultron'' made it a specific point to show that the Avengers were doing everything they could to keep civilians out of the line of fire, and the implication was that they had essentially succeeded until ''Civil War'' showed otherwise.
** In the ''Film/IronMan'' movies (especially ''2''), Tony suffers from unresolved issues due to his parents' death in a car accident when he was young. ''Film/CaptainAmericaTheWinterSoldier'' puts a darker spin on it by dropping a heavy hint that their deaths were [[spoiler:actually a HYDRA assassination]], though this information is seen by Steve and Natasha, not Tony. ''Film/CaptainAmericaCivilWar'' takes it further, as not only is the hint confirmed and revealed to Tony, but it adds the detail that [[spoiler:Steve's brainwashed friend Bucky carried out the hit.]] Tony is furious that [[spoiler:Steve had kept this from him for two years and is now protecting his parents' killer.]]
** ''Film/{{Guardians of the Galaxy|2014}}'' has Yondu remark that Peter Quill's father was a "jackass" when one of the Ravagers laments they didn't deliver Quill to him. Come ''Film/GuardiansOfTheGalaxyVol2'', [[spoiler: Yondu is proven right when Quill meets his biological father Ego the Living Planet, who wants to eliminate all life in the universe by replacing it with extensions of his Celestial self. Ego had even killed hundreds of his own children after they were delivered to him by Yondu and didn't have his Celestial gene. Yondu even dies trying to save Peter, meaning that he truly became Quill's father figure after he was abducted. It also has the effect of taking the RunningGag of Yondu going soft and making it so he was fiercely protective of Peter and helped him learn to survive on his own.]]
** At the start of ''Film/{{Thor}}'', Odin banished Thor and stripped him of his power after Thor nearly started a war. ''Film/ThorRagnarok'' shows that Odin [[spoiler:had to imprison Hela after she grew out of control in her desire for conquest, meaning now Odin banishing Thor had more to do with stopping Thor from becoming a monster like Hela was than merely trying to teach him humility.]]
** In ''Film/CaptainAmericaCivilWar'', Tony nicknaming his holographic therapy machine [[FunWithAcronyms B.A.R.F.]] is treated as an offhand joke. In ''Film/SpiderManFarFromHome'', we see that its inventor [[spoiler: Quentin Beck]] was outraged that Stark ridiculed his life's work with such a demeaning nickname. [[spoiler: This was the catalyst that led to Beck becoming a supervillain and endangering thousands of lives in his quest to make himself look like a hero. Though it's obvious that he was already mentally unstable and Tony would have taken him a lot more seriously than he probably imagined.]]

* ComicBook/UltimateXMen: The twist that mutants are an artificial race created by Weapon X devalues the entire Xavier/Magneto ideological struggle and reduces the mutant race a whole from the legitimate next step in human evolution to a deluded race of Transhumans with delusions of grandeur.

* The long-forgotten ''Creator/MarvelComics'' mini-series ''Conspiracy'' implied that most of the FreakLabAccident and MillionToOneChance-based {{Origin Stor|y}}ies from UsefulNotes/{{the Silver Age|of Comic Books}} were actually the work of a shadowy government cadre called "Control". So any silly story conceits that could be dismissed as a PlotHole or TheoryOfNarrativeCausality were actually implied to have been caused deliberately. The reason [[ComicBook/FantasticFour Reed Richards and his friends]] were easily able to sneak into space, as well as the reason their rocket didn't have proper radiation shielding? Control. The gamma bomb test that transformed Bruce Banner into Comicbook/TheIncredibleHulk? Control. The wildly unsafe radiation experiments witnessed by [[Franchise/SpiderMan a certain schoolboy from Queens]]? Control.

* ''Franchise/SpiderMan''

** Norman based the [[Characters/MarvelComicsNormanOsborn Green Goblin]] on an imaginary boogeyman figure that haunted him throughout his childhood, especially whenever his abusive father would lock him in the abandoned Osborn estate.

* ''Franchise/XMen''

* ''ComicBook/{{Nextwave}}'' was insanely violent and nonsensical, utterly hilarious, and completely non-canon. And then in ''ComicBook/MightyAvengers2013'', [[ComicBook/MonicaRambeau Spectrum]] finds out that the villains of Nextwave, the Beyond Corporation, are back. She goes off on a quiet, angry rant about the impossible things she faced, being forced to kill, being changed by the Corporation, and nobody ever believing any of it really happened, even thinking it was a joke. Then she flashes into her Nextwave trenchcoat (but in black).

* ''ComicBook/{{Nextwave}}'' was insanely violent and nonsensical, utterly hilarious, and completely non-canon. And then in ''ComicBook/MightyAvengers2013'', [[ComicBook/MonicaRambeau Spectrum]] finds out that the villains of Nextwave, the Beyond Corporation, are back. She goes off on a quiet, angry rant about the impossible things she faced, being forced to kill, being changed by the Corporation, and nobody ever believing any of it really happened, even thinking it was a joke. Then she flashes into her Nextwave outfit.

** Felicia Hardy, aka The Black Cat, was initially just a laidback adventuress who became a thief because it was fun (and to help break her father out of prison). In ''ComicBook/SpiderManBlackCatTheEvilThatMenDo'', it is revealed that she was raped by her boyfriend, Ryan, in college. The experience led to her becoming bitter and angry, and she became the Black Cat with the intended purpose of killing Ryan for revenge. Unfortunately for her, Ryan died in a car accident, denying Felicia her vengeance and leaving her without closure. Feeling that her life had been stolen from her, Felicia turned to a life of theft.