History Fanfic / IncidentZero

All For One and All Might's fight takes place a bit earlier than in canon, and more importantly resulted in both of their deaths. This caused a series of ripple effects that result in a very different, much harsher Japan than in MHA canon. It also resulted in a dying All For One giving Izuku his quirk, telling him "it's your world now."

** Bakugou still bullied Izuku in school and has the temper and ego the size of Japan. However, he's also got a strong sense of justice that manages to throw ''[[BlackAndWhiteInsanity Stain]]'' for a loop, is willing to break the law to try to save civilians, and wastes no time in calling out the Hero Commission when their restrictions and political maneuvering get people hurt. When presented with the existence of the Meta Liberation Army, who practice an actual supremacist ideology, he's disturbed. He also has slightly more justification for being angry at Izuku, if not for bullying him, compared to canon since he clocked onto the fact that Izuku (accidentally) stole his friends' quirks before anyone else, even Izuku himself, did.

** Dabi himself is either a nominal hero or an outright AntiVillain. He is ready to do ''anything'' to take his revenge on Endeavor, including being ready to kill Uraraka for stumbling onto their plans until Shouto forces him to stop, and giving Shouto false promises that he won't kill Endeavor when everything's over to keep his brother on his side.

* BotheringByTheBook: After All Might's death, the hero commission brings all hero schools directly under their control, as well as stripping all non-hero curriculum like business and support courses. They do something similar with hero agencies, bringing them directly under their command to deploy as they see fit unless they can secure private funding. Nedzu's response? [[LoopholeAbuse Registering UA High School as a private hero agency headed by himself under which the staff are workers and the students are apprentices or support staff, ensuring that at least a little of All Might's brand of heroism remains alive.]]
* BrainwashedAndCrazy: Hawks has been subjected to constant brainwashing for two years to turn him into the perfect weapon for the Hero Commission. Shinsou is horrified that his own mother did this to one of the few heroes on the commission's payroll that tried to live up to All Might's ideals.

* CrapsackWorld: After All Might's death, Japan went to hell. On one end, villains, yakuza groups, and other criminal organisations became embolden in the aftermath of All Might's death. On the other end, the Hero Commission that was supposed to keep things together deliberately make things worse by making it almost impossible for independent heroes to exist at the exact time Japan needs as many heroes as possible to deal with the skyrocketing crime rates.

** Izuku has all the quirks of All For One stored in his body, plus a few more he's accidentally stolen since copying it. However, he's only able to use a very small subsection of them thanks to his body having a limited-but-growing ability to use them.

* CorporateSponsoredSuperhero: The only remaining option beside retirement or vigilantism for heroes who don't want to be under the direct control of the Hero Commission is to seek independent funding from other sources such as corporations.

** Lots of people were killed by the fight between All Might and All For One. These include All Might, All For One, Hisashi Midoriya, Toga's parents, and Kyouka's father.

* DidntSeeThatComing: When All for One gave his Quirk to Izuku, [[spoiler:he was expecting to take over Izuku's body. But Izuku being Quirkless messed with his plan and his Quirk became Izuku's instead of remaining under the original weilder's control]].
* DisabilityImmunity: Izuku being Quirkless made it possible for him to resist [[spoiler:being taken over by All for One after the latter forced his Quirk on him since Izuku had no Quirk to fight and takeover]].
* DisappointedByTheMotive: Class 1-A finds Mustard's motivations to attack them, [[spoiler:being embarrassed of his aunt's, ''Midnight's'', entire theme as a hero]], to be completely underwhelming and Shoji suggests he's really just using it as an excuse for his own despicable nature.

* EnemyMine: Having a mutual enemy in the Shie Hassakai, Stain's group and Nighteye's agency agree to a temporary truce to take down some of their soldiers, one of their highest lieutenants, and a pro-hero in their pockets. It ends after Stain and Spinner kill one of the yakuza since Nighteye and his sidekicks cannot let that slide. Stain is fine with that since it help proves Nighteye and his sidekicks are some of the few actually good heroes left.

** Kyoka Jirou is famous as a singer, writing songs that represents the negative moods Japan is feeling after Incident Zero.

* FantasticRacism: Quirk-based discrimination has gotten worse after Incident Zero. Quirkless abuse has always been common, but society as a whole are treating those with significant mutations even worse than before, and even so-called heroes openly treat people with quirks considered villainous with disdain.

** The UA Entrance Exams are completely reworked by the time Izuku and his friends apply to them. With the significant decrease of funding, they can no longer afford to do large-scale battles against robots.

* FreudianExcuseIsNoExcuse: Katsuki is unsympathetic to [[spoiler:Dabi's abuse at Endeavor's hands as his justification for villainy, pointing out that many other kids suffered abuse without becoming murderers like Dabi. Burnin agrees with his sentiments, but points out that the general public won't since Endeavor is both the current Number 1 hero and has existing reputation problems]].

* GreyAndBlackMorality: The conflict between Endeavour and the Meta Liberation Army is one between a man who means well and does some good but is also responsible for a lot of bad things, and a group that's hell bent on liberation of meta abilities no matter the cost, even if that cost is tearing society apart.

* ScrewTheRulesIHaveMoney: Because of the Hero Commission rolling back HeroInsurance and funding for independent heroes, the financially distressed heroes have become morally-compromised and are more open to taking bribes from people with enough money.

* XanatosGambit: So far, this is how the MLA seems to operate. They encourage the Hero Commission to become more totalitarian in the hopes that it will stir up public opinion against them, eventually priming the populace for a full revolution. In the mean time, they can use their own ties to the Commission to acquire more resources and information. They also intend to encourage Endeavor and Bakugou to rebel against the Commission's tight restrictions, so that they can hold them up as either shining examples of the effectiveness of free quirk use if they succeed, or as martyrs if they fail.

* ShoutOut: All for One says "I love democracy" as a reference to ''Film/StarWars''.

''[[https://www.fanfiction.net/s/13653270/1/Incident-Zero Incident Zero]]'' is a ''Manga/MyHeroAcademia'' fic by Ya Boy Guzma ([=AO3=] link [[https://archiveofourown.org/works/27451000/chapters/67108621 here]]).

* GreyAndBlackMorality: The conflict between Endeavour and the Meta Liberation Army is one between a man who means well and does some good but is also responsible for a lot of bad things, and a group that's hell bent on liberation of meta abilities no matter the cost.

* HeroWithBadPublicity: Endeavour has a bad reputation with the general populace for, among other things, excessive collateral damage and his role in making Japan worse by supporting the laws that made being a proper hero harder. It gets worse after [[spoiler:Dabi takes advantage of the media attention on the USJ incident to reveal Endeavor's DomesticAbuse. Especially with Shouto talking about the abuse. If it was just Dabi, the validity of his allegations would have been questionable at best, but Shouto backing up the claims leaves little room for doubt]].

* {{Cliffhanger}}: Chapter 43 ends with [[spoiler:Izuku meeting the vestige of All for One for the first time]].

* TheReveal: Chapter 42 reveals [[spoiler:Tenko has One for All]].

''[[https://www.fanfiction.net/s/13653270/1/Incident-Zero Incident Zero]]'', is a ''Manga/MyHeroAcademia'' fic by Ya Boy Guzma ([=AO3=] link [[https://archiveofourown.org/works/27451000/chapters/67108621 here]]).

Unmarked spoilers for both the fic and the My Hero Academia manga ahead.

!!Incident Zero contains examples of the following: