Shahryar - The 'initial' PoD is Midoriya being born with Mastery instead of biologically quirkless (as he was in TTB before obtaining One for All). Also this ain't a polycule, this is a menage a trois aka a love triangle. Also, I didn't see those movies either xD
(***)
Eleven Years Ago
"Izuku." Hisashi says. His massive physique makes him slightly intimidating, and that's even when he isn't actively trying to be intimidating. "No, you can't become a pro-hero. And we both know it."
They are in their home, Izuku decided to finally confront his father about it. Discovering what sort of villain he exactly was has already put quite a rift between him and Inko, something that was going to result in their total separation… but it hasn't quite happened yet.
"I-I'm going to do it." Izuku refuses to back down, staring back at his father with cold determination on his face.
If not for himself, then for his siblings. Their father was, Izuku could see that clearly, hoping for them all to become villains under his tutelage.
They didn't want it, but it was clear that their father's carefully crafted mentions of the black sides of heroism and the more 'constructive' forms of villainy was somewhat influencing, especially with the number of decent supervillains that hanged around their home.
But… then there was Izuku. The same Izuku that refused to yield. The same Izuku that Asa looked up to as a role model. The same Izuku that helped Aiko figure out her quirk and was always there for her when people at school started to be freaked out by her behavior.
Worst (or best) of all, it was rather clear that Tenko was leaning heavily toward Izuku over their adoptive father. That left only one of them that was clearly preferring Hisashi. Everyone else looked up to Izuku (although Tenko was rather… calm about it).
And Izuku wanted to become a hero.
Hisashi Shigaraki (the fact that they're all calling themselves Midoriya once more now says everything about the split in their family) looks down at Izuku and sighs.
"Very well." He then says. Izuku stares at him in surprise. "If you manage to get into a hero school and graduate, that is. I was actually planning to move out, due to the recent… disagreements with your mother. There'll be no further pressure from me on anything whatsoever. You can pick any hero school in the country and I'll pay for it for the whole time."
"W-what's the c-catch?" Izuku mumbles out.
"Why does there have to be one?" Hisashi tilts his head a little. "Your view on the hero society is, as I stated multiple times, unrealistic. You have a brilliant mind, but no, they won't care about it. Since you're consistently refusing to see reason, I'm going to let you see it for yourself."
"And y-you won't…"
"I will not intentionally sabotage your attempt." All for One replies. "By which I mean the fact that I will not change any of my plans to accommodate for you. If my plans include an attack on whatever hero school you somehow managed to get in, I'll still execute them as if you weren't there. However, I will not target the school if I have any other way of achieving my goals. That is…" He grins lightly. "If you even manage to get to one."
"I will." Izuku manages to steel himself for a change. "I will become a hero and t-then one day, I-I'll see you j-jailed."
"Sure you will." All for One smiles. "I'll naturally have you go under a loyalty quirk to make sure that you don't tell the heroes anything about me. Other than that… good luck, Izuku. Let's see if you find any hero that is willing to believe in your dream as much as you do."
(***)
"Kid, you can't just roll in and ask for a meeting with All Might." The receptionist at the Might Tower sighs loudly. "This is the third day you've been here. You can't…"
Izuku doesn't let her finish.
"P-please, I know that you probably get a lot of people saying that, but I really, REALLY am a relative of someone that was very close to him." Izuku cuts in. "All that I need you to do is to relay my name to him. I'll go home and stop bothering you if you do. I p-promise."
The receptionist sighs. All Might is a decent enough guy, he probably won't make it a problem if she does that to keep a kid happy and doing something productive rather than almost camping at Might Tower.
Besides, if he is so ardent about it, maybe there is something to it.
"You know what, fine." She surrenders. "Your name?"
"Shimura." Izuku lies. "Shimura Izuku."
The fact that it wasn't actually a lie was something he discovered much later, to his great surprise.
(***)
Seven and a Half Years Ago
"And THAT'S your plan for winning the war?" Izuku - wearing a business suit, courtesy of Re-Destro and Trumpet - asks incredulously, staring at All for One.
The demon lord looks way less intimidating when surrounded by all the machinery that's keeping him alive, its regular beeping reminding them all that the broken mess in a wheelchair was still alive.
He is still terrifying, but… manageably so. It's rather that he isn't enjoying that fact in the slightest.
They are both accompanied. To All for One's right side is Entropy, wearing some nondescript trousers and a T-Shirt, clear discomfort visible on her face. She is playing with one of her twintails, although it's clear that it's the nervous type of playing. To his right side is Kurogiri, his preferred way of dodging death.
Izuku came with Uraraka in her T-Shirt +shorts combo (not like she needs any protection measures whatsoever), Hypothermia in a long dress and Juggernaut in his light body armor.
The atmosphere is … tense.
"Armageddon is our masterpiece." All for One replies. "With it, we'll be able to finally break the siege of Deika and start gaining ground nationwide. Finishing it will take Doctor Garaki a moment longer, but…"
"No." Izuku cuts in. "Through the power vested in me by Re-Destro, I officially veto the deployment of Armageddon."
Silence in the room. Entropy looks like she forgot how to breathe for a moment. Then again, so did All for One.
"You what?" All for One clearly didn't like being shocked to this degree.
"I said that Armageddon will not be deployed." Izuku - no, he is here as Notebook - cuts back. "The terms of the alliance between the Meta-Liberation Army and the League of Villains state that you and Re-Destro are equal co-commanders of the Paranormal Liberation Front. You're both allowed to veto the decisions of each other, for as long as they're done as co-commanders of the PLF. Re-Destro can't dictate anything to the League of Villains just as you have no say about the inside operations of the Meta-Liberation Army. However, deploying a weapon of mass destruction is something that has to be done on the PLF level, and I say no."
"Are you sure…" All for One replies coldly. "... that you have Re-Destro's agreement on that? His precious city is besieged by the JSDF and the pro-heroes, I believe…"
Izuku pushes the phone through the table between them. All for One, despite being blind, catches it easily. Midoriya was kind enough to push the right buttons.
"Feel free to ask him about that." Izuku replies coldly. "He saw the recording from the inside of the Armageddon preparation chamber already." Skeptic was as useful as ever.
Less than a minute later, All for One puts the phone down, with an expression of sheer, livid fury on what was left on his face. There was a time when Izuku Midoriya would cower at that (even now, Hypothermia and Juggernaut are clearly almost frozen by it), but today? Today he doesn't care.
All for One killed the part of him that cared in Kamino. Now he was paying the price for that. Or, to be exact, the interest for it. Paying the debt itself was something left for the future.
"You goddamn pest." All for One says, venom dripping off his tongue. "You're enjoying it, aren't you?"
"More than you could possibly imagine, father." Izuku smiles. "You're really not used to having to cooperate with someone to equal you, are you? All that loneliness of being the top bitch of this country for almost two centuries must have gotten to you in the end."
"Your precious Re-Destro is just an overly ambitious upstart that…" All for One decides to strike back.
"My precious Re-Destro…" Izuku cuts in. Oh, how he loves doing that. "... has an army. More than one hundred thousand followers, disciplined enough to actually battle the heroes like equals and dangerous enough to hold them at bay on Deika's outskirts for months now. What do you have, my dear father?"
"I have…"
"You have an army of rapists, racists and mad scientists." Izuku continues, ignoring AFO's attempt at interjection. "The Quirkless Liberation Front is the only part of your 'army' that actually follows orders. There is a reason why they are the only group that Re-Destro permitted to support the Deika's frontline. You're the side of this alliance that has problems fulfilling their obligations, not Re-Destro. If that's the end result of you plotting the downfall of the Hero System for two centuries, then do yourself a favor and pick up another hobby. Besides, riddle me this, father."
He smiles widely. Oh, he is enjoying it so very much. He was waiting for that for years. It took Re-Destro quite a while to resurrect his self-esteem and give him some much needed confidence. But he enjoyed the results immensely.
"You gave us an effectively quirkless nerd." He says. "We gave you a human-sized weapon of mass destruction in exchange. So how the hell did you manage to lose Geten while I'm still around, kicking and being useful, pray tell me? Because, between the two of us, it tells us a lot about the differences between you and Re-Destro. And then, there is the big question."
He makes a mockery out of a thinker pose. All for One probably sees it through his sensory quirks. He's clearly seething with rage, but says nothing… for now.
"You've managed to leverage Re-Destro into an alliance with you…" Izuku says. "... by providing intel suggesting that the HPSC knows about the MLA and is preparing the Paragons in secret for the decapitation strike against it. So please, tell me exactly, why was the HPSC' reaction to the MLA insurgency so incoherent and filled with genuine-looking surprise? Because neither me, nor Re-Destro, can figure this out."
"This meeting…" All for One says slowly. "... is over."
"Suit yourself." Izuku rises from his chair. "Entropy, Tenko asked me to relay a message to you. He wants a word with his sister. Preferably right now."
Entropy glances at AFO, then her eyes are back on Izuku.
"Sure." She says. She's probably relieved that the meeting ended. "Kurogiri, warp me with him."
(***)
Entropy is deeply surprised by a visible lack of her brother in the vicinity once she steps through Kurogiri's warpgate. It's the Midoriya's apartment in Deika, close enough to see the Detnerat Tower from the window up close.
No Tenko. No Inko. No Aiko. Asa is there, sitting in his villain outfit (it makes him look like Mr. Compress with a different color scheme, but it was probably the goal), playing with a deck of cards by the window.
He might be fourteen years old, so he isn't technically a villain yet, but it's clear that his career path was already decided.
Juggernaut, Uraraka and Hypothermia bid them farewell and leave the apartment quickly.
"So…" Hokori Shigaraki - once known as Hana Shimura and, to the world, Entropy - says once they left. "... what is it about?"
"I just want to have a talk with you." Izuku says. "Without anyone knowing. Asa is here to… keep things civil, so to say."
So he probably touched his brother and was ready to issue states when needed. Like, say, Quirk-Resistant to make her own quirk almost useless. And she was fairly sure that he was way better than her in quirkless combat.
Fine.
She sits down on a couch by the coffee table. She has a feeling that Rabbit is staring at her from under his mask, but if so, he doesn't make it known.
"So… where's mom?" Entropy asks. Yeah, she clearly took her father's side in the debacle, but she was still close enough to call Inko that way. Especially as she has all but forgotten her biological one.
"Out, having a social life." Izuku replies. "Perks of being a supervillain in a city inhabited by villains and having your oldest son be mentored by the supervillain overlord of said city."
"I still can't believe that they are making parties and all that high life bullshit despite being under siege." Entropy groans. She's waiting to see what it's all about. In the meantime, if it's small talk, she's alright with participating in it.
Besides, it was rather clear that this was a progress. They weren't super close to begin with - it was Tenko that was Izuku's friend - and then things changed into an abject, one-sided hatred after the USJ and the Training Camp. Izuku was actually wishing to talk with her again.
"Deika has the strongest Anti-Air defense out of all cities in Japan nowadays." Izuku replies. "Besides, the JSDF is too busy trying to knock the MLA and QLF out of the trenches on the city approach to bombard Deika. Re-Destro decided to keep acting as if there was no war whenever possible to maintain morale."
That made sense, especially with Kurogiri to bypass the blockade and deliver supplies to the cities. She disliked it, but… it made sense.
"You saw Armageddon." Izuku suddenly speaks again. Ah. End of small talk. "Please, answer me this one question. Is a man that wants to unleash this thing upon the general population someone who you truly want to conquer Japan for?"
Entropy stares at him in shock over the table. What? Why? Did Notebook ever hear of something called subtlety?! If that was an attempt to make her more loyal to Re-Destro than to AFO, then… yeah, no.
"I… don't really mind it." She decides to admit it. "It's a weapon. A nasty one, yes. But if a weapon isn't to some degree nasty, your skills as a weaponsmith are shit. If it's deployed in a controlled way, it'll…"
"Do you truly and honestly believe…" Izuku cuts in. "... that All for One will deploy it in a controlled way?"
That thing again.
"Look, I do admit that father's… not the nicest man." Entropy decides to play the open cards. "But we both know that he was much less nasty before Kamino. Being injured to this degree does that to people. Stop acting like he was a total devil from day one and…"
"Tenko." Izuku replies shortly.
"We both know that all you have is a theory." Hokori retorts. "Yes, Tenko has the toe joints suggesting quirklessness, but we both know that there are cases of people manifesting quirks with them, without All for One around. It's rare, but it happens. Besides, my quirk is a natural one and very similar to his."
"And what if…" Izuku replies. "... your meta-ability isn't a natural one?"
Silence in the room. Only after a few seconds does Entropy manage to speak.
"What?" Yeah, an understandable reaction.
"Did you see Garaki's new High-End?" Izuku replies. "The aerial supremacy one?"
"Only heard about it." She replies cautiously. "Almost killed Majestic, didn't it?" Izuku nods. Yeah, that particular engagement was a success for the PLF, although in Notebook's opinion they could achieve much more if the noumu was assisted by the MLA or QLF rather than ISP.
"It has several meta-abilities, including Yoroi Muusha's Arsenal and…" Izuku stares at Hana quietly for a moment. "... one oddly resembling Nana Shimura's Flight."
"So what?" She failed to connect the dots. "He probably got it from someone because it resembled hers. Or he managed to get Garaki to replicate it from her blood. I would have done the same in his seat, Nana Shimura certainly proved that this quirk had potential even besides One for All and…"
"My present theory is as follows." Izuku says calmly. "That's not Nana Shimura's flight. It's yours. All for One took it from you before it manifested and gave you Entropic Touch, all while giving Tenko his Decay… and then just waited for his lack of inborn quirk factor make his meta-ability go berserk on first manifestation, so that he could then heroically 'rescue' you from the aftermath of his own plot."
"No." Hokori shakes her head. "No no no and no. I don't believe in that, I won't believe in that. All you have is conjectures. You hate him, and shit, I know where it all comes from even if I disagree, but it makes you always expect the worst from him and… look, I'm sorry for how it all played out, fine? If I knew that you were studying on the UA and that I was attacking your class, I'd ask father to change the target for another school, but after the USJ we were…"
She doesn't really mind murder. She likes the thrill of battle. But that particular school and those particular students… she had to admit that she didn't like the result.
"I have a counterargument for that." Izuku interrupts her coldly. "Something of a family secret that you're yet to hear about. I believe… that hearing it out will change your outlook on our father." The last word is, as always when AFO is mentioned by him, filled with venom.
"I…" Hokori's eyes meet those of her younger brother (if not by blood). "... dare you to try it."
(***)
Seven Years Ago
All for One, despite missing his lower body and his precious life support, is a tenacious bastard. Even now, he was still trying to crawl somewhere, leaving a trail of blood and some other things behind him.
This won't stand.
"You absolute fucking bastard!" Entropy shouts while delivering a kick to his side. All for One left some sort of strained whimp of pain, the fact barely halting his desperate gasps for air. "I trusted you! I treated you like a father! And I was just a toy for you the whole fucking time?!"
With Aiko's eyes on him, his quirks (aside from AFO itself) are sealed. Oh, he might be able to activate something in the briefest of moments when she blinks, but it's not long enough to activate something truly deadly.
Tenko decides to join in the fun, delivering his own kick to the side of AFO's head. It's strong for some of the teeth to come out.
The demon lord was being undone, one blow at the time. And damn, if it wasn't enjoyable.
Asa was busy patching up Izuku in the background, after the really nasty injury he suffered before Tenko decayed All for One's life support machinery. Aiko was keeping his arsenal of quirks sealed, staring at the crawling demon lord with quiet intensity.
"Hokori Shigaraki is dead." Entropy announces before delivering another kick. "I'm Hana Shimura once again. And I'm fucking done with you."
"Wow, late arrival to the game but I really like your enthusiasm, Player Three." Tenko replies with a triumphant grin on his face. He abandoned the name Tomura years ago.
Then he kicks All for One again.
Hisashi Shigaraki abandones whatever fruitless struggle he was attempting. He rolls over, face up, still gasping for air, but it's clear that his attempts are slowly dying down. His reign of terror that lasted for almost two centuries is finally coming to an end - at the hands of the kids that he picked up to change them into villains to equal or surpass him.
Oh, the irony of that was simply delicious.
It gets even better when Hana stomps on his face with her combat boots. More broken teeth. The cracks in the scarred tissue that made up for his face. She was waiting for that moment for more than a year now, ever since Midoriya shared their 'family secret' with her.
All for One unleashes his final card. Some shapeshifting mini-noumu hidden under his business suit. It leaps towards Aiko, managing to break her line of sight for a moment before Tenko manages to get it off her face and decay it to dust.
All for One called up for hyper-regeneration quirk and some life-support one. For a brief moment his breathing got steadier and he almost managed to grab Hana's leg while powering up Air Cannon with his other hand and trying to fire it at Aiko.
He only grazed Hana instead. She promptly pins his hand to the ground with her boots, squashing it like a bug. Before he can fire Air Cannon, Aiko gets him under her quirk again,the quirk failing him alongside Hyper-Regeneration and Life Support.
This time his cards are spent. Hana and Tenko beat him to death a moment later, Tenko selectively decaying his neck so that Aiko could take his head for whatever nefarious reasons she wanted it for.
"Time for the clean-up." Hana announces. "Izuku?"
"Sure thing." He looks exhausted, and is still badly injured… but the wide grin on his face speaks volumes. "Tenko, decay him completely. Asa, deal with our favorite family doctor."
"Okay." The figure in a Mr. Compress-like outfit gives him a thumbs-up before walking to the edge of the room. Doctor Garaki is there, unconscious and on the floor. Asa gives him a slap.
"Conscious." He then says. Doctor Garaki snaps up, his eyes immediately landing on the corpse of All for One.
"WHAT HAVE YOU D…"
"Gullible." Asa says after touching his hand again. "All for One died in Deika."
"W-what?" Doctor Garaki stares at him in shock.
"All for One died in Deika." Asa says. "You only imagined him being here and you tending to him since then. After all, your closest friend for more than a century just died, it's natural for you to feel loss and have hard times coping with it."
He is doing remarkably well, Izuku decides offhandedly. Izuku wasn't the only one who benefited greatly from Re-Destro's tutelage. No more anxiety left, just cold determination.
"Oh." Doctor Garaki looks down. The body is almost entirely disposed of. "I… guess? But what happened here?"
"There was a small accident with your newest noumu." Asa replies. "It hit you in the head and made you unconscious, so some slight memory loss is understandable. You probably forgot the noumu in question entirely, didn't you? We've come to save you. Sorry for Aiko leaving a hole in the wall, by the way."
"Oh." Doctor Garaki blinks while Asa helps him stand up. "Thank you, I guess. I must be getting sloppy, to get caught like that by a noumu."
"How exactly did you make him somehow more terrifying than Aiko…" Hana says towards Izuku. "... is beyond me."
"Shame that overusing it on someone makes them more and more senile and irrational." Izuku cuts back. "I think it's time to go home to celebrate, and… then we have a war to win."
That they do.
(***)
Six Years Ago
The Haiboro Woods are on fire. Dabi's last stand to give the remains of the League time to flee or regroup caused at least several major forest fires. The PLF's communications are down, and the heroes are everywhere.
Entropy is running away
Her left arm is broken in several places after Nejire Hadou's Nejire Blast. She is suffering from quirk-exhaustion. The last time she saw any of her comrades was at least five minutes ago.
It was Muscular. He wasn't of much help, with his neck clearly broken after Fat Gum (she barely recognized the corpse, he was so goddamn thin)'s final punch. Unless there was a pocket of resistance that she somehow missed, it was no longer a fight. Just heroes rounding up the survivors.
Her ears were ringing, and whatever blow she received from Hadou made her… confused. She was still trying to recover her bearings, but… the battle was clearly over (she barely remembered it) She had to escape. Everything else was secondary.
Kurogiri was down, and with the League destroyed, the war was practically over. Hana Shimura didn't care about it for now, though. She had something more pressing on her mind.
She had to get to Midoriya, he had to…
"There you are." She hears a voice. She looks at its direction and… Lemillion. On his face, fury. "Not so terrifying and confident anymore, Entropy."
Shitshitshitshit.
"You…" Entropy is cornered. Entropy is lost. Entropy lost. She has to get out of it somehow, or… she has to survive this. No matter what. She always did, right? "Just listen to me, you…"
He vanishes underground. She is too tired and quirk-exhausted to move fast enough to dodge the punch that sends her flying, breaks her nose and gives her a concussion. Despite it she manages to stand up, but…
"That was for Sir Nighteye." Lemillion replies while walking towards her. "The next one is going to be for Suneater. One of the heroes you just killed."
The main hero assault group. Entropy powering up her Large-Scale Aging. She barely remembered the faces she saw crumbling before her. Crust was there, that 'Suneater' guy probably as well, and…
"No, you…" She tries to say before realizing that it won't work and that she has to fight her way out of it.
Well, fucking fine. She likes it that way either way.
She fires out one of her additional quirks (she only had a few extra quirks, she was more like a slightly better Nine than AFO reborn and this was going to…), the Flamebreath. But it phases through him. He had to realize how long she could maintain it from seeing the recording of her past battles, and he counted it.
By the time he is physical again, her quirk is out of fuel. He grabbed some large piece of rock from the forest floor and slammed it into the side of her head, dislocating her jaw. She falls back onto the floor on her back, Lemillion not giving her a moment to try to call up for her remaining quirks.
The official version was that Entropy was cornered by Lemillion and defeated in a fierce battle of quirks. The true story - that only one person knew about - was that she was beaten to death with a piece of rock.
(***)
"I…" Hokori's eyes meet those of her younger brother (if not by blood). "... dare you to try it."
Well, damn if he didn't. Discovering that your 'random adoption' might not have been as much of a random thing (especially with all of your siblings being related to your father's past nemesis) truly changed her outlook on things.