History Sandbox / MyHeroAcademiaAllForOne

* ClippedWingAngel: Driven to the edge both physically and mentally All For One desperately unleashes all of his Quirks at once with his ultimate move Omni-Factor Unleash: All for One Goal, in order to kill Bakugo and overpower Tomura all at once. The move turns All For One into his ideal demon lord form, a nightmarish amalgam of seemingly everyone whose Quirk he's ever absorbed that towers over the city and rockets through buildings like they were tissue paper. However, at this point All For One has lost control of his emotions meaning his iron clad control of the stolen Quirk factors has slipped causing his powers to no longer work in tandem. His new form is also so big it means he's not very mobile once he's stopped by Bakugo's explosions. All of this causes All For One's ultimate move to turn him into a giant target that Bakugo proceeds to blow to pieces, the end result of which turns him into an infant (which All Might states would have happened even if the attack had worked).

* DeathGlare: As he's trying to fly off to rescue Tomura, he's still smug in the face of Hawks' attempts to stop him...until Hawks' points out Endeavor already ''beat'' him, prompting a [[SoreLoser hateful glare]] from All For One.

* DetrimentalDetermination: Whilst his sheer commitment towards embodying the role of a comic-book villain so utterly were what allowed him to carve out a successful generations-long reign as Japan's ShadowDictator, by the final arcs it becomes clear that his same desire to [[ControlFreak control the narrative of the story]] to play out the way he wants it to be ultimately [[HisOwnWorstEnemy one of his biggest flaws]].

* DiscOneFinalBoss: {{Zigzagged|Trope}} Despite being the one of the two [[BigBadDuumvirate Big Bads]] of the series, he's defeated at Kamino and imprisoned by the climax of part 1 of the story, leaving Tomura as the new leader of the League of Villains. Then All For One's plans see his consciousness [[HijackedByGanon possesses Tomura]] and frees his original body from prison. But then, during the FinalBattle, fighting both the Heroes and Tomura's mental struggle from within on two fronts causes his control to slip, allowing Tomura to destroy his vestige and become Izuku's [[ArchEnemy sole final opponent]] once again. This is solidified in chapter 410 when All For One's original body is deaged out of existence after all the cumulative damage he had received from the heroes and Bakugo's NoHoldsBarredBeatdown in the previous chapter leaving Izuku and Tomura's battle the climactic final fight of the series.

** PlayedWith. All For One truly seems to care for his younger brother, Yoichi. Despite his rebelling against him, he repeatedly tried finding a middle ground. He gave Yoichi a Quirk to help him get stronger, even making sure his body would be able to handle it. His love is such that he even shed BerserkerTears while killing Kudo in clear anger over Yoichi's death. However, it is clear that he sees his sibling as an extension of himself, rather than a full person, and his quest to take One For All can be seen as him trying to retrieve a piece of himself that refuses to comply. This is best shown when they interact in the vestige world of One For All.
---> '''All For One''': It's such a shame that I could never make you mine!
** At first, he seemed to genuinely care about Shigaraki and wanted him to be his successor, but like his brother, he sees Shigaraki as little more than an extension of himself and he was merely grooming him to becoming his next vessel.

* AbusiveParents: Zigzagged and then ultimately played straight. He appeared supportive towards his adopted son at first, but his ultimate goal to merge with Tomura against his will shows he never cared about him at all. He just saw him as an extension of himself.

* BackFromTheDead: Twice over: His flashback to All Might's first victory over him makes it clear he genuinely ''was'' killed by him, with his head turned into liquid, only for Garaki to somehow revive his body after stealing it from the morgue. This occurs again with him being [[ThereIsNoKillLikeOverkill nearly vaporized]] by Endeavor's flames, but this time he came prepared with a trump Card in Eri's Rewind.

* BookEnds: The very first Quirk All For One ever stole was him mothers Spearlike Bones Quirk which he instinctively took when he was a baby. After he has been beaten so badly by Bakugo that he has deaged back into a baby the final Quirk he instinctively uses in a desperate attempt to kill his opponent is his mother's Spearlike Bone Quirk

* BreakThemByTalking: The sheer ease with which he's able to get under someone's skin is practically a Quirk in its own right, and he shows ''far'' more skilled ability in enraging others than any particular Quirk he possesses, either giving him a psychological advantage or smug enjoyment at their animosity. [[LaserGuidedKarma somewhat fittingly]], Bakugo ultimately defeats him by [[FeedItABomb exploiting]] the fact he never shuts his mouth in a fight.

* RageBreakingPoint: Happens to him at several points throughout the final arcs. He openly curses Star as the "spectre of All Might" as he's one-sidedly damaged from the inside by her last gambit. His image of outward composure finally shatters when the heroes break his imposing mask, causing him to viscously lash out at them screaming in a rage over his humiliation. When he's being pinned down by their united efforts and realises that he's expending more of his remaining lifespan the he can afford to from their barrage, he hits another one of these, channelling the feeling directly into his Quirks to empower them, overwhelming both the heroes and the limitations of his physical body as he does so, with only Rewind keeping him 'alive'. He expresses [[WhatIsThisFeeling unfamiliarity with the sensation]], believing that it comes about from his PsychicLink to Tomura allowing him to ''actually'' experience deep-seated rage for once, rather than something he could always do. This implies that despite his furious displays prior, he ''still'' wasn't truly feeling angry deep down.

* RuleOfSymbolism: Due to using Rewind to try and cheat death in the final arc, he spends the FinalBattle gradually aging in reverse, which is accelerated when he takes damage. By the time he finally reaches his intended targets, he's reduced down to a child, emphasizing that for all his grandstanding and boasting, he's just a PsychopathicManchild who never grew beyond being an orphan boy reading comics and searing to be a Demon Lord.

* SoreLoser: His taking his loss against All Might and his subsequent imprisonment well was entirely because he made plans about his plans being carried out in the future and eventually breaking out. In reality, he can't stand the idea of losing and this is why he makes exhaustive plans to ensure he wins. When things aren't going his way during his final clash against the heroes, All for One resorts to complaining and ranting like a pathetic loser, employing extreme and desperate tactics to ensure he stays on top.

* ThisCannotBe: At his core, All For One is so narcissistic that he simply ''can't'' comprehend the possibility he might genuinely suffer an actual loss or set back, or bare to admit he did if there's some excuse he can make to avoid it. As such, his default reaction to ''any'' set back or loss he suffers is disbelief it could happen at all, causing a rapid-fire string of these to occur as the FinalBattle steadily turns against him, eventually falling into delusional denial of reality.

* BeneathTheMask: Throughout the series, All For One has had the air of a dignified EvilOverlord who plans for everything and is always in control. However, the final arcs show that, as that mask cracks, he's even more childish and bratty than Shigaraki.

* DespairEventHorizon: Downplayed once One for All's vestige manages to reclaim possession of Tomura's body. The once cackling villain who [[IRejectYourReality straight up deludes into thinking his plans are going better than they actually are]] is reduced to somberly accepting hat his primary goal has failed. While he still goes through with his long-term goal of taking over the world, he lost all enthusiasm for it, labeling it a pointless endeavor. It seems he was being sincere about how, without Yoichi, his actions are all for nothing.

** Upon reclaiming control of Tomura's body, his vestige fails to smile, and simply expresses a dour, almost hollow expression as he goes to simply kill Deku. As he observes, his entire plan--use Tomura's hatred and strength of will to steal One For All-has been foiled, and Yoichi is gone from him once more. All he can do is resign himself to his meaningless goal of taking over the world, no longer hiding the emotionless sociopath he is at his core.

** Upon reclaiming control of Tomura's body, his vestige fails to smile, and simply expresses a dour, almost hollow expression as he goes to simply kill Deku. As he observes, his entire plan--use Tomura's hatred and strength of will to steal All for One--has been foiled, and Yoichi is gone from him once more. All he can do is resign himself to his meaningless goal of taking over the world, no longer hiding the emotionless sociopath he is at his core.

* OOCIsSeriousBusiness: Rule of Thumb: If that smile of his leaves his face for ''any'' length of time, it's a sign things aren't going well for him. He maintains it as much as a sign of his supreme confidence in his victory, but as events turns against him time and again throughout the final battle, this is eventually wiped off his face for good and replaced with a angry scowl at his inability to sieze even a minor victory by demoralising his beaten foes.

* NotQuiteDead: Although All For One himself has deaged himself out of existence, his vestige still survived in Tomura, merely suppressed and biding the time to take over when Tomura is too emotionally weak to hold him down.

* HiddenDestainReveal: For most of the series All For One speaks of Tomura like he's someone precious to him as his adoptive father who wants his protege to succeed. Even after he steals Tomura's body for his own plans All For One states that he has nothing but respect for his protege's wishes and that they can both achieve what they want together. However, in chapter 418, once Tomura's willpower wavers thanks to Izuku's efforts, the remnants of All For One's vestige emerge and consume him while showing just how much contempt All For One has for him.

* NotQuiteDead: Although All For One himself has deaged himself out of existence, his vestige still survived in Tomura, merely suppressed and biding the time to take over when Tomura is too emotionally weak to hold him down.

* ChekhovsSkill: His "Forcible Quirk Activation" was initially demonstrated at Kamino Ward when forcing the unconscious Kurogiri to create an exit portal for the League. This ability means that when he's later full-body paralysed by Stain's [[TheParalyser Bloodcurdle]], he can still activate his Quirks, and uses that t activate Bloodlet to [[BloodFromEveryOrifice messily]] escape his predicament.

* YourHeadAsplode: Implied to be what All Might did to him in their decisive battle five years prior to chapter 1, and only survived through his Garaki's help. The only parts of his head that aren't scar tissue are his mouth and jaw, allowing him to still flash his trademark SlasherSmile.

* SanityHasAdvantages: His delusional obsession with comic books and superhero/villain tropes causes him to make multiple mistakes and faults in his planning that comes to a head in the Finalbattle, gradually depriving him of every advantage he possesses or causing him to needlessly waste the ones he has out of an insane commitment to being recognised as the ultimate villain through inspiring despair and hopelessness in others. Case in point: he falls for literally the oldest trick in the book by making his execution of the helpless All Might a long drawn-out affair, which gives Bakugo just enough time to race in and rip his ultimate victory from his arms.

* OverdrawnAtTheBloodBank: Aware Stain was against him ever since he escaped Tartarus on his own, All For One held a few Quirks, Bloodlet and Antigen Swap in reserve to counter his Quirk, should it ever be used against him. When Stain does successfully ambush him alongside All Might, he escapes through using Bloodlet to [[BloodFromEveryOrifice force all his paralysed blood out of his body]], leaving him briefly covered in his own blood and Antigen Swap to change his blood type to render Bloodcurdle ineffective.

* ChekhovsSkill: His "Forcible Quirk Activation" was initially demonstrated at Kamino Ward when forcing the unconscious Kurogiri to create an exit portal for the League. This ability means that when he's later full-body paralysed by Stain's [[TheParalyser Bloodcurdle]], he can still activate his Quirks, and uses that to [[BloodFromEveryOrifice messily]] escape his predicament.

* OverdrawnAtTheBloodBank: Aware Stain was against him every since he escaped tartarus on his own terms, All For One held a few Quirks in reserve to counter his Quirk, should it ever be used against him. When Stain does successfully ambush him alongside All Might, he escapes through using his contingency to [[BloodFromEveryOrifice force all his paralysed blood out of his body]], leaving him briefly covered in his own blood.

* CannotTellFictionFromReality: {{Downplayed|Trope}}. All For One learned PragmaticVillainy from modelling his behaviour on the Demon lord from Yoichi's comic books, and a combination of his sheer power and versatility in a fight allowed him to dodge reality checks for generations, leading to him believing, on some level, that the world ''does'' work on comic book logic, even if he supplants it with actual intelligent manipulation and foresight gained from his years of experience. However, his inability to [[CantCatchUp adapt with the changing times]] or face the reality of his situation ultimately undoes him throughout the Finalbattle in a ''massive'' HumiliationConga.

* CannotTellFictionFromReality: {{Downplayed|Trope}}. All For One learned [[PragmaticVillainy]] from modelling his behaviour on the Demon lord from Yoichi's comic books, and a combination of his sheer power and versatility in a fight allowed him to dodge reality checks for generations, leading to him believing, on some level, that the world ''does'' work on comic book logic, even if he supplants it with actual intelligent manipulation and foresight gained from his years of experience. However, his inability to [[CantCatchUp adapt with the changing times]] or face the reality of his situation ultimately undoes him throughout the Finalbattle in a ''massive'' HumiliationConga.

* CannotTellFictionFromReality: {{Downplayed|Trope}}. All For One learned pragmaticVillainy from modelling his behaviour on the Demon lord from Yoichi's comic books, and a combination of his sheer power and versatility in a fight allowed him to dodge reality checks for generations, leading to him believing, on some level, that the world ''does'' work on comic book logic, even if he supplants it with actual intelligent manipulation and foresight gained from his years of experience. However, his inability to [[CantCatchUp adapt with the changing times]] or face the reality of his situation ultimately undoes him throughout the Finalbattle in a ''massive'' HumiliationConga.

* TheSocialDarwinist: Having [[SelfMadeMan raised himself up from absolutely nothing]] through taking and monopolising off others sicne the moment of his birth, All For One fully embraces this belief. To him, it doesn't matter how much willpower and determination you have. If you don't have any strength or resources he can steal for his own benefit, you're worthless.