Fanfic / Entropy: The Fate of the Hero System

Entropy: The Fate of the Hero System is a My Hero Academia fanfiction series by NotBurgerKing that explores a possible way that the canon story can unfold after Chapter 401.

Ever since her humiliating loss at the hands of Fumikage Tokoyami in her first Sports Festival, Momo Yaoyorozu has faced an uphill struggle to be recognized for her potential as a hero. The deck was stacked against her from the start, with the Sports Festival not allowing her to pre-make equipment, but it's too late to rehabilitate the image most heroes got of her on that fateful day: an indecisive, incompetent hero who only got where she did because of her family's wealth and connections, her friends too naive to understand her problems.

So if the world won't let her help as a hero, she'll have to force the world to change as a villain.

Despite the similar name and theme, this fic isn't related to My Hero Academia: Entropy.

Works in the Entropy series:

• The Everything Villain: Arsenal, completed January 23, 2023
• Kota's Hero Academia: Rise of the Ultimate Villain, ongoing

Tropes in the Entropy series include:

Recurring Tropes in Both Stories

• Accusation Fic: Both stories go to great lengths to call out many issues NotBurgerKing finds in various characters and aspects in the MHA world, particularly the nature of the hero system, as well as U.A. and how the school is run.
• Adaptational Villainy:
  • The very premise of the fic is that Momo Yaoyorozu ends up becoming "Arsenal", a Visionary Villain who does battle with her former classmates who didn't already join her in the "Fallen Hero Alliance", after failing to strike out on her own as a hero due to 0% Approval Rating, and seeing society as refusing to change in spite of the events of the Paranormal Liberation War. Even considering the motivations, it's still ultimately a far cry from Momo's canon self, who was a Hero through and through and Endearingly Dorky to the point she got flustered over visiting a department store.
  • Melissa Shield has gone from someone still willing to help heroes in spite of her father's actions on I-Island, down to even building a suit of Power Armor for All Might's final battle with All For One, to invoking Then Let Me Be Evil after being vilified just for being David Shield's daughter and being Momo's main supporter.
• Cast Herd: In addition to the various characters making up the Hell Class, there are pro-heroes, villains, government staff, social media personalities, and the members of the Fallen Heroes Alliance. The second story takes this even further, bringing in an entire new 1-A and 1-B for Kota’s run at U.A., some of whom are minor characters from canon, while others are wholly original.
• Macross Missile Massacre: Momo’s “Combined Arms Strike”, which unleashes a barrage of gun and missile fire on whatever unfortunate villain she’s targeting.
• Powered Armor: Developing this becomes the key to Momo’s success as Arsenal. Melissa develops a baseline suit of armor for her, with various hard points that allow Momo to create new weapons and components as she needs them.

The Everything Villain: Arsenal

• 0% Approval Rating:
  • Momo Yaoyorozu/Creati: Due to her loss to Tokoyami in her first year Sports Festival (where she was pushed out of bounds before she could create a single weapon to defend herself), she is seen as incompetent. Combined with her decision to intern under Uwabami, and cast in the light of a post-war Japan that doesn't blindly trust heroes, she's seen as a Rich Bitch whose parents bribed UA to let her in. Notably, her vigilante persona, Arsenal, is not subject to this, by virtue of nobody knowing who Arsenal is under the mask (until the Rebound Agency find out).
  • Melissa Shield: Many people consider her an accomplice in the events of My Hero Academia: Two Heroes, despite her genuinely being unaware of the plot until it was revealed.
• Adaptational Jerkass: Mei Hatsume. Unlike her canon depiction where she is a well-meaning if socially inept inventor, here, her negative traits are taken to their logical conclusion: she invents solely for the sake of inventing, changing the parameters of a support request on a whim simply because she wants to work with a different technology. This even extends to asking Melissa Shield about the Quirk Enhancer, the MacGuffin of My Hero Academia: Two Heroes, despite the fact that the events of Two Heroes are the reason Melissa was ostracized and was at UA in the first place. NotBurgerKing has stated they deliberately wrote Mei like this due to considering her canon personality to just be fanon flanderization, and claims Mei is The Sociopath on par with Kyudai Garaki.
• Broken Pedestal: Izuku Midoriya to Momo Yaoyorozu, for many reasons, which ultimately lead Momo to pull a Face–Heel Turn and descend into villainy. For starters, he suggests Hatsume as a support engineer to Momo, despite Momo's (correct) gut instinct that Hatsume just wants to use her as a human 3D printer. Then, he refuses to accept that Momo is having difficulties with her hero career, since he sees her for the powerhouse she is, so clearly everyone else must see it too. Then, as if the previous points weren't enough, he sponsors the Heroic Contributions Act, the enactment of which ultimately leads to the end of Momo's hero career as The Everything Hero: Creati, as despite her vigilante activities allowing her to put in actual work, she still falls short of the cutoff. She ultimately comes to the conclusion that he's too much of a Wide-Eyed Idealist to fix the actual problems plaguing society.
• Catch-22 Dilemma: The crux of the fic. In order to prove herself capable, Momo must have opportunities to do so, opportunities she is denied because she hasn't proven herself capable. This eventually leads to her losing her hero license under the new Heroic Contributions Act; she is regularly rebuffed when trying to solve cases since people see her as a Spoiled Brat. This leads to her not making the cutoff under the HCA.
• Face–Heel Turn: Momo Yaoyorozu and Melissa Shield, as well as the entirety of the former Class 2-A. They become the Fallen Heroes Alliance.
• Inherent in the System: The ultimate conclusion Momo reaches regarding the flaws in hero society.
  The whole thing was nothing more than a thinly-veiled, government-sanctioned form of autocracy. No matter how many people demanded changes and reforms to "improve" it, it could never be truly fixed; not when its very existence depended on granting privileges and the right to enforce the status quo to a small fraction of the population, and on keeping the rest of the population forcibly dependent upon this elite minority.
• Innocently Insensitive: Izuku Midoriya, due to his personal belief that Momo is a great hero, refuses to accept that she is having problems with her hero career.
• Leonine Contract: Hatsume's deal with Momo. Momo needs better support gear in order to perform better as a hero. However, Hatsume is only willing to offer said support gear as long as Momo is willing to give her whatever she wants in terms of supplies and gadgets. Furthermore, since Hatsume is seen as a sort of god to the other support students, Momo doesn't even have the choice of going to another student, not that any of them would treat her better than Hatsume. It takes Melissa Shield arriving at UA to break Momo out of the deal.
• "The Reason You Suck" Speech: Momo delivers a short one to Izuku after realizing he doesn't understand how societal norms play into society's problems.
  Momo: Midoriya, I know that you've already inspired millions. You're going to usher in a new, fairer hero society, and I'm sure that that society will regard you as a new pillar to uphold it. But it has become clear to me, from the conversation we just had, that your desire to help other people is far greater than your ability to recognize how best to do so. [uses her Quirk to don her hero costume, ditching her dress and gown]
  Izuku: Yaoyorozu, wait—
  Momo: You'll never be a Symbol of Hope to me.
• Then Let Me Be Evil: Melissa proposes this after Momo argues they would be seen as villains if Momo kept acting as a vigilante despite losing her hero license.
  Melissa: If we end up becoming villains as part of continuing to help as many people as we can, maybe it would be worth it.
  Momo: [shocked] Mel-Melissa— did you just— Melissa, think about what happened when your father went that far. Think about how much of your problems since then resulted from that.
  Melissa: Yes, and because of that I've already spent the last six years of my life being treated as a villain in the eyes of the public. I have nothing left to lose by actually becoming one, and neither do you. Sometimes you have to put your foot down and make a stand even if the entire world seems to be against you.
  [...]
  Momo: [grateful] But Melissa, you don't have to go that far just for my sake.
  Melissa: It's not just for your sake, it's for mine as well. I'm tired of pretending I'm fine with the way I'm treated by the world. If people will only see me as a villain, if people will only allow me to be a villain, perhaps that's who I should be, just to spite them. And if we end up arrested and jailed, or even killed, like so many other villains-so what? You know that we're already heading towards disaster. Our reputations have made sure of that. We might as well send the world a message while at it.
• Vigilante Man: Momo, by necessity, for the latter half. Though she has a hero license, people refuse to work with her hero persona due to false allegations regarding her ability in a fight. As a result, she moonlights as the titular Arsenal, using a different costume and hiding her face, and claiming Arsenal's takedowns as her own in order to up her case-solve rate. Unfortunately, it's not enough to escape the Heroic Contributions Act, leading to her going full vigilante and eventually pulling a Face–Heel Turn.
• Wide-Eyed Idealist: Izuku Midoriya, despite claiming he wants to fix the problems with society, ultimately fails to understand the crux of the problem.
  Because he didn't care for such motivations, he'd overlooked this critical detail when he pushed for the Heroic Contributions Act, failing to realize just how much heroes required external validation to function. His "Just do your best" mentality implicitly demanded that every hero should try to succeed in their goals without any consideration for the causes behind the obstacles they may face, and implied that any hero who failed to live up to their potential had only themselves to blame for it regardless of their circumstances. Most importantly, he idolized the hero industry far too much to even contemplate the idea that the field of heroism should be allowed to die out, even as he himself acknowledged and attempted to correct some of its flaws.

Kota's Hero Academia: The Rise of the Ultimate Villain

• Accidental Murder: Kota's water blast attack against Doromichi during their match ends up accidentally dissolving the slime girl's body, nearly killing her in the process. Word of God confirms the only reason she survived is because her quirk functions as such that she can come back from the dead as long as her body doesn't get diluted to the point of it completely disappearing; the only way to permanently kill her is to dilute her in such a large volume of solvent that her body completely dissolves into it at the molecular level.
• Apathetic Teacher: Aizawa, natch. Who is one of the biggest reasons Momo became Arsenal.
• Ascended Extra: Aside from Kota, several members of the new 1-A and 1-B are characters who debuted as children in canon, including Tsuyu’s younger sister, Satsuki, as well as several elementary students who appeared during the Remedial License Arc.
• The Atoner: Mawata Fuwa is immensely guilty over her originally voicing support for Aizawa after the whole class expulsion he pulled on her class, which left them with a black mark that resulted in them being unable to obtain any meaningful work as heroes after graduating, which led to the death and disappearance of several members. She subsequently has a fear of taking leadership positions (due to having been the class representative at the time and losing the faith of the rest of her classmates) and a tendency to be willing to sacrifice herself to make a plan work.
• Awesomeness by Analysis: Izuku may be painfully naive, but he’s still no slouch mentally, being the first person to figure out that Arsenal doesn’t have multiple Quirks, but rather an extremely flexible Quirk with a wide array of applications.
• Back from the Dead: Doromichi actually died after Kota's water blast, the only reason she was capable to be saved is because thankfully there was still enough of her body left to regenerate, as well as the timely arrival of first aid.
• Beat Them at Their Own Game: This is one of the two main strategies of Momo and the rest of the FHA for taking down the hero system. As Arsenal, Momo shows herself to be vastly superior at taking down villains than Japan’s pro-heroes, undermining the myth that only heroes can be trusted to take on crime with their Quirks. This occurs simultaneously with their second main strategy of revealing the scandals and misdeeds of heroes to further undermine people’s faith in the system.
• Boring, but Practical: Shinomura possesses a Quirk allowing him to control technology within a short radius of him, which is very effective in the Battle Trials, but not flashy enough to be considered for hero work in the eyes of society which gave him a deep hatred for those with "heroic" quirks.
• Calling Card: Arsenal/Momo paints her insignia, both at the scene of her takedowns, as well as on the criminals themselves, as a way of making sure people know that it was she, and not a hero, that was responsible for it.
• Curb-Stomp Battle: While it isn’t shown, Arsenal/Momo’s fight with Bakugo was this, ending with Momo defeating him easily by cooking off the sweat on his hands and catching him in his own explosion.
• Crippling Overspecialization: Several characters note that hero training is geared more towards promoting close combat, which is flashier and more visible, as opposed to the more pragmatic approach of using ranged attacks to take down an opponent before they can fight or flee. Momo/Arsenal makes extensive use of the latter strategy, which is part of what has made her so effective as a vigilante.
• Cool and Unusual Punishment: After his stunt at the Sports Festival, Shinomura is forced to go under extensive close combat trainning under Aizawa. It wouldn't be so bad, except for the fact that Aizawa, in a especially petty move, forbids him from taking any trainning other the one he will force onto his student, like using his Quirk, which will cause an inevitable case of Crippling Overspecialization and cause the boy to fall back considerably in his development.
• The Dreaded: Arsenal is feared throughout the criminal underworld, due to their seemingly unquantifiable power, and the long list of criminals they have captured or killed, which, by the start of the story, has reached over a thousand.
• Didn't Think This Through: Yuka decides to attempt to beat Haru by charging at them while using her own uniform as cover by shape-shifting into darkness, forgetting until it's too late that while she is intangible in darkness form, her uniform isn't, causing her to be eliminated from the tournament in seconds.
• Disappointed in You: Izuku loses a great of respect for Kota after he nearly kills Doromichi during their match, and while we never get to see what exactly what he said to his protegee, his cold treatment as well as Kota's regret paint a very bad picture.
• Entertainingly Wrong: Shinso, and others, assume that Arsenal is actually a Nomu leftover from the PLW, unleashed by All For One as a final attack on society before his defeat, believing them to be using multiple Quirks. Of course, Arsenal is actually Momo, using her Quirk to create various weapons and devices that allow her to emulate virtually any Quirk imaginable.
• Evil Versus Evil: The Alliance has been at war with several villain factions since they started to make their move, with the CRC standing out as their primary adversary outside the Heroes.
• Gone Horribly Right: Yuka's plan to use Hiragawa's sandstorm as cover to unleash her Quirk and steal everyone's flags in a Kansas City Shuffle goes so well, not even the audience notices she used her Quirk, and instead they attribute her victory to Hiragawa, denying her a lot of attention.
• History Repeats: Yuka's arc parallels Momo's arc in this story as she, a promising recommendation student with a powerful Quirk, is left unable to use it in the tournament, thus ending up on the wrong end of a Curb-Stomp Battle and being forced into a Catch-22 Dilemma as her reputation plummets.
• Irony: Momo was driven to villainy due to the severe flaws plaguing hero society, exacerbated by the increased cynicism of the public and their shaken faith in the hero system following the Paranormal Liberation War. However, it is shown that many of the villains she takes down as Arsenal are people who have been similarly forced into villainy by the same societal factors that Momo is seeking to combat and are thus among the very people she is supposed to be helping.
  • Momo takes an interest in Yuka as a potential successor, unaware that Yuka's inspiration for becoming a hero is Tokoyami.
• It's Personal: While Momo and the FHA are driven by the desire to reform society to ensure that people don’t suffer the way they did, it’s also shown that they have a very personal stake in going after U.A. and their former teachers, Aizawa in particular, for how they were screwed over during their time in school.
  • Momo also decides to keep an eye on Yuka for this reason, as she notes that there are many parallels between them to the point that she is willing to consider Yuka a potential successor should she fail to topple the hero system as Arsenal.
• Ironic Name: The name of the task force created to hunt down Arsenal is "Strike Force Athena". Athena is the Greek goddess of associated with wisdom, warfare, and handicraft, traits that fit Yaoyorozu perfectly.
• Kansas City Shuffle: Operations Cavalry and Bletchley form one. The former is a full-on frontal attack against the USJ on the 10th anniversary of the Hell Class' USJ attack, while the latter is a cyberattack on UA that aims to expose more corruption in the hero society to galvanize support for the Fallen Heroes Alliance's cause, allowing them to move ahead with Stage 2 of their long-term plans faster than originally intended.
  • Operation Bletchley itself counts as one. Technocrat will try to hack into UA, drawing Nezu's attention, and while Nezu is dealing with that, Skinjacker will attempt to infect UA's systems with a virus allowing the Alliance full access to UA files.
• Karma Houdini Warranty: One of Momo’s first major actions in the story is invoking this for Mineta, with Operation Winepress, using cyberattacks to leak Mineta’s history of sexual harassment to the public and having him finally be punished as a result.
• Logical Weakness: Satsuki has a frog mutation Quirk like her sister, and as such absorbs most of her oxygen through her moist skin. When Hiragawa creates a sandstorm in the Sports Festival's second event, she is unable to breathe for the duration of the sandstorm and nearly suffocates.
• Not Quite the Right Thing: Izuku is shown to be trying to affect positive change in society by pushing for reform to the hero system. However, his efforts are ultimately shown to be doomed to failure as the hero system itself is too fundamentally flawed to continue.
• Offscreen Villain Dark Matter: Inverted and lampshaded. A politician notes that U.A. spends far more of its budget than necessary on Awesome, but Impractical contraptions for the Sports Festival, such as flying castles.
• Pragmatic Villainy: The Alliance's war against other villain groups acts as both an effort to get rid of rival factions, as well as a good publicity stunt to bring the public to their side. In fact, their campaign against the CRC led to the approval amongst the heteromorph community.
• Shrouded in Myth: Arsenal is a mysterious figure to Japan at large, as no one knows their Quirk, gender, or even more basic statistics, like height and weight. Instead, they are largely viewed as a truly superhuman figure, possibly with multiple Quirks at their disposal, capable of truly impossible feats. This is in large part to their speed, as they often resolve a situation and take off before anybody can get a proper view of them, or attack from long distance. Also Momo and Melissa are constantly improving Momo’s armaments and suit, which changes her appearance over time, making it harder for anybody to nail down anything concrete, to say nothing of the tools she creates, which allow her to emulate any number of Quirks.
• Switching P.O.V.: The story switches between its cast of new hero students and its villains, as well as featuring news articles and social media posts where appropriate.
• Skewed Priorities: Played with. When Shinomura hijacks U.A.'s broadcast systems with his Quirk to deliver the audience (and hero society) a "The Reason You Suck" Speech, many decry him as villainous for his Smug Snake attitude and his Boring, but Practical Quirk. Hatsume, who is watching the Sports Festival, plans to recruit Shinomura, realising how useful his Quirk is for her inventions.
• Secret-Keeper: Deconstructed. Midoriya still hasn't told anyone about what Todoroki said to him during the Sports Festival, even several years later. When the FHA find a video recording of this during Operation Bletchley and post it online, people are quick to call out Midoriya for keeping quiet about the abuse for years. His fans try to defend him by pointing out that no one else would have believed him, but this falls flat when Midoriya publicly admits that it was a genuine mistake and apologises rather than defend himself, further intensifying the backlash.
• Too Clever by Half: Naoko's decision to use her Teleportation Quirk to win the first event of the Sports Festival comes back to bite her once she learns that taking her flag is an Instant-Win Condition in the second event.
• Took a Level in Jerkass: Aizawa is shown to be even more harsh and judgmental than before. In addition to being openly Quirkist, he’s dropped virtually any pretense of actually being a teacher, never providing any actual instruction and always answering any requests for guidance or clarification with some variation of “if you can’t figure this out on your own, you’re too stupid to be in the hero course.”
• Villain Protagonist: Momo Yaoyorozu/Arsenal, as per her Face–Heel Turn at the end of The Everything Hero: Arsenal, as well as the rest of the Fallen Heroes Alliance.
• Xanatos Speed Chess: Momo and the FHA are forced to adapt their plans in the wake of Momo’s defeat of Bakugo as Arsenal. While Momo had always intended to take on and defeat her former classmates, she had not planned for one of those confrontations to occur so early in her projected timeline. It has the consequence of causing the HPSC to fast-track Arsenal to S-Rank villain status and ramp up their efforts to take her down. While Momo had always planned on defeating her former classmates, she had largely planned on doing so after doing a more thorough job of undermining the public’s faith in them to ensure that her victories look justified, and her victims wouldn’t be made into martyrs.

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