Jpx099 - ... this chapter should offer you some of that lol.
fencer29 - Let's just say that AFO is going to hate Nedzu by the end of this fic xD
BlackChappie - Soon, very soon :P
(***)
"A lab…" Izuku blinks at him. "Your quirk is an artificial one."
"Precisely!" Nedzu replies. "I was one of the very few cases of successful animal quirk implantation, a part of the final stage of trials before the Council, before its heyday for the record, moved over to human tests. Regretfully, I'm most likely the only test subject that survived to this day… but, well, let's go through it chronologically, shall we!"
"Go on." Izuku replies as dryly as he could.
"The history of quirks started around thirty years ago." Nedzu replies. "The beginnings of the phenomenon weren't exactly glamorous. Certain young and ambitious scientist, here in Japan by the way, discovered something extraordinary. A genuine superpower manifestation in someone from their extended family, something that he managed to confirm beyond any reasonable doubts. His nam…"
"Wait." Midoriya cuts in. "That's not the beginning of quirks, just of humans realizing that they exist."
"Yes, yes, we'll get to that." Nedzu replies. "The scientist's name was Yoichi Shigaraki. He immediately realized that he was onto something great. So, he did as scientists sometimes do in moments like that. Asked his older brother, at that time a National Diet member, for support. His brother, Hisashi Shigaraki, realized the value of what his brother discovered, and set out to help him."
"From the name being mentioned earlier as a part of a worldwide conspiracy…" Izuku says. "... I assume things went wrong."
"Oh, eventually they did, but we're far from that point." Nedzu replies. "Hisashi Shigaraki has managed to, through some backroom deals, obtain the support his brother needed to set up a small research laboratory, get a few competent helpers and all the resources he needed. By luck, or perhaps a divine inspiration, that's a perfectly rational being speaking with zero mockery whatsoever, Yoichi Shigaraki succeeded in deciphering the big mystery behind the nature of quirks."
There is a pause after those words. When it gets uncomfortably long, Izuku decides that he is supposed to say something.
"That mystery being…?" He says.
"I have no idea!" Nedzu says. Once again, despite the mechanical voice, there is something akin to cheerfulness in his tone. "Don't look at me like that, Midoriya-kun! Yoichi was obsessively paranoid about the truth. The amount of believable lies he conjured had the Council and the rest of its scientists fooled completely. I have something resembling a theory, though."
"That being?" Izuku decides to push slightly more.
"I believe that Yoichi suspected quirks, especially the emitter and transformation ones, to be a form of narrow reality warping." Nedzu replies. "He believed them to come from an outside source, humans being merely relays for particular frequencies of them, capable of somewhat guiding the output. The 'biological' side of quirks were adaptations to said power, making us better attuned to them.
"That… makes an awful lot of sense." Izuku admits. When Nedzu's head tilted to the side a little, he decided to elaborate. "We've tried to figure out the quirks for months now, and… science simply refuses to cooperate. But if they truly are a form of reality warping, it's not that surprising, because…"
'...because they, at least when activated, write their own rules." Nedzu replies. "Correct. We might never know what the true progenitor of quirks is. Yoichi seemed to refer to them as the 'Musician', he tended to use a lot of music metaphors when quirks were involved. For some reason. Well, that's all that I know, or even suspect, when the actual birth of quirks is involved. I, however, also know a lot about what happened later.
"That… might be what I'm most interested in learning." Izuku admits. Nedzu actually nods at the screen. Yeah, he sounds like someone interested mostly in being… practical.
"Absolutely understandable." The rat then says. "Yoichi managed to isolate twelve different genes among the vast collections of 'junk DNA', at least one of them present in the entirety of the human population. He dubbed them the Minus-Ultra genes. Before you ask, they didn't 'cause' quirks. Quite the opposite - having even a single one of Minus-Ultra genes prevented the manifestation of the meta-abilities."
"What?" That provoked a reaction from Izuku. He wasn't exactly a biologist, but this sounded a bit like… "How's that…"
"You're assuming that possessing meta-abilities is an evolutionary positive." Nedzu cuts in. "Think about it. Imagine that you are a neolithic hunter that just evolved an ability that makes you able to hear the thoughts of the animals, maybe even speak to them. Would you still hunt them as efficiently if you could feel and hear their pain? Another example. What if you awoke, let's say, a fire quirk… but happened to live during the times of the witch hunts? What do you think would happen to you then?"
"You're telling me that the meta-abilities were locked by so many genes because… those without them were more likely to survive and have children?" It's a bit hard to imagine for Izuku, especially with how awesome the abilities were, but…
"It's just theories." Nedzu replies. "We can only speculate. Even if someone, like the metahuman that Yoichi discovered, happened to be born without the Minus-Ultra gene, what were the chances of them finding another metahuman to have a child with? And if they had a child with a quote unquote normal person, the chances of any of their offspring to be born without Minus-Ultra gene were relatively small, especially when the other person carried several of them."
That… somehow makes sense. Izuku is clearly out of his depths, but…
"A practical example." Nedzu continues. "Year 1066, battle for Stamford Bridge. A lone, 'giant' Norseman with an axe holds the bridge against the English army, slaying forty of them. An incredible feat… for a normal human. But if he actually had some sort of general strengthening quirk, akin to what your friend Paladin has? How would modern science confirm or reject that theory? Go elsewhere, find a saint healing with a touch - what if they had something similar to what little Eri has? A monster in the woods or a river, maybe an early mutant like Kappa? It's easier to just say 'legends and overexaggerations', isn't it?"
He even knows about Eri? Shit.
"Another one of Yoichi's theories…" Nedzu continues, ignoring Izuku's silence. "... is about a past mass extinction. Have you ever heard of the Toba supervolcano eruption?"
"Errr, yes?" Izuku vaguely remembers it from school. "It happened… 60 thousand years ago? Caused a bottleneck in the human evolutionary tree by causing a major extinction event worldwide."
"Around 70 thousand, but otherwise correct." Nedzu replies. "What… if the eruption wasn't natural?"
"What?" Izuku blinks a few times. "What do you mean?"
"Imagine a scenario." Nedzu replies. "Early humans live peacefully. Some of them have meta-abilities. Not all bloodlines, some of them just had to possess naturally occuring Minus-Ultra genes. With every passing generation, some of those lines bred with those quirkless, eventually growing weaker or at least remaining stagnant in terms of power. You didn't need a knowledge of modern genetics to realize that 'power holders' often had powerless children when they had them with powerless people. So, they stuck to their own, to a large degree that is. As a result, every subsequent generation was more and more tuned to the quirks as a phenomenon, growing stronger and stronger. What do you think will happen eventually?"
Izuku has no idea. Nedzu, after a solid ten seconds of silence, continues speaking.
"Yoichi referred to this as Quirk Singularity Theory." Nedzu replies. "I might use a fake identity to publish it eventually, unless the Council will do it for me first. First stage Quirk Singularity is when human bodies begin to fail under the strain, resulting in either deaths of the hosts or rampant mutations as their bodies attempt to adapt, further increasing output as a side effect. You can consider all these minor mutations like what your friend Earworm has, to be a form of minor biological adaptations, a sort of teaser of what's to come. Second stage Quirk Singularity happens when meta-abilities are too powerful not for their holders, but for the world."
"The supervolcano." Izuku realizes what it is about now. "You think that it was a quirk?!"
"Perhaps some earthquake or volcano eruption inducing." Nedzu replies. "It's not like the early people knew what a supervolcano was, now did they? They could set it off entirely on an accident. There was no worldwide communication back then to coordinate an anti-metahuman pogrom in response to the disaster, so the process continued. Surviving human populations continued to climb the ladder towards the Singularity. Some were wiped by lesser cataclysms caused by meta-abilities. Some realized what was happening and eliminated those that were too powerful among them. As a result, the scientists estimate that only three to ten thousand humans survived planetwide."
"... and the communities with the highest chances of survival were the ones without powerful metahumans." Izuku realizes. Nedzu nods. "So the majority of those that survived were quirkless, perhaps from a group that rejected the metahumans as a whole."
"Natural selection at its finest." Nedzu concludes. "The quirks offered an evolutionary edge… but eventually killed their holders. The ones that continued spreading their genes and rebuilt the population were those without quirks, the few surviving metahumans forced to crossbreed with the quirkless. Eventually, everyone, save for some random mutations born without Minus-Ultra genes, were quirkless. Or, so Yoichi suspected. It's all a theory, theoretically sound but without solid material evidence."
It's… a rather terrifying theory. Izuku is going to have a serious talk about it with Mei, Aizawa and Principal Sasaki, at the very least. But for now…
"How does that connect to the meta-abilities manifesting left and right?" Izuku asks.
"We'll get there in a moment, no need to be impatient." Nedzu replies. "You see, Yoichi made two more practical discoveries. First one was a gene-therapy that erased Minus-Ultra genes of the subject, allowing for a natural manifestation of quirks. However, it merely allowed it. Even without the Minus-Ultra genes, the quirks manifested at random, and only in a small percentage of the population. What's more, the first generation quirks tended to be either very weak or very strong. It's only in the second generation, the one with at least one first gen quirked parent, that the phenomenon more or less stabilizes. Before you ask…" Nedzu says when Izuku opens his mouth. "...cases like the one of your friend Hijack are rare. The Council estimated that 98% of the second gen quirkeds came from parents whose quirks were too weak to be noticed, despite the Council's tests clearly showing an active quirk factor."
That made sense, but…
"Amplitude has a dual, controllable quirk." Izuku counteracts. "His brother has an unstable first generation quirk. How does this work?"
"A fascinating genetic anomaly." Nedzu replies immediately. "Something previously unforeseen, even by me. His brother… Dabi, I'm going to guess… must have been born without a quirk whatsoever, being the exact opposite of Amplitude who was born with a mixture of two quirks. Dabi was then hit by a first gen quirk activation, and one of fire. Unless we talk about extreme case of coincidence, that would suggest that there are some biological and psychological factors into the nature of the quirk one awakens, Dabi inheriting those factors from their parent with a latent fire quirk, without said quirk, and then awakening his own fire quirk, due to said factors."
"Does that mean that we're going to keep getting more 1st gen quirkeds?" Izuku replies. That would be the worst case scenario, they assumed it to be temporary and…
"Most likely, yes." Nedzu nods. "If it makes you feel any better, it'll decrease in intensity as time passes. You have nine times as many latent quirk holders as active ones, meaning that eventually all awakened quirk will have pre-adaptation into human psychology and biology, due to at least one of their parents having a latent quirk. So, aside from extreme cases of incompatibility, all quirks will be stable, even if the active quirkeds will still be a minority."
That explained Tsuyu, Izuku realizes suddenly. If those truly are her siblings… one of their parents had to possess a latent frog mutation quirk, not strong enough to manifest, but strong enough to make their every child a frog mutant.
"The second of Yoichi's discovery… I think it's time to return to the main subject… was the ability to create artificial quirks." Izuku opens his mouth, but Nedzu speaks first. "No, I do not know HOW it worked. Only Yoichi did. And he made sure to bury that knowledge."
Izuku is… relieved, actually? He has no idea what was the exact scope of the 'artificial quirk creation', but it sounds like something too dangerous to be around. Even when born at random, quirks were a pain to deal with. Having a group be able to produce them? The implications were terrifying.
"That's how the Council of Twelve was born." Nedzu says. "A group that could serve as an evidence for the wisdom of the saying that hell is paved with good intentions."
"You said that it was a worldwide conspiracy." Izuku says, drawing out words. "Don't tell me they used the artificial quirks to run a world domination scheme."
"Oh, they absolutely did." Nedzu confirms his worries. "The two brothers looked at the world and saw injustice, pointless wars, discrimination, poverty… and figured out that they just obtained something that could alleviate all those problems. After all, you just needed someone sufficiently smart to run the show properly, right?"
Izuku groans loudly. He could list like two dozen videogames, comics or manga that clearly showed why that was a bad idea, most of them vaguely superheroic in theme. Clearly both Shigarakis missed out on them.
"That's like the worst idea I ever heard of." He announces. "And on so many levels at once. Starting from the ethical issue of, well, world domination without being elected to be a president of the world or anything like that, and ending on the fact that scientists with their tendency to go for 'rational' options don't strike me as someone capable of navigating the mess that a human society and laws are."
"Oh, you're absolutely correct!" Nedzu agrees with him. "The Council founders were a bit too… idealistic, so to say. The two brothers found a few fellow-minded individuals throughout the world, and in a matter of few years the Council of Twelve was formed. Twelve men, each one responsible for an oversight of a certain part of the globe, with Hisashi being the councilor number one responsible for East Asia and Yoichi becoming the council's chief scientific advisor, almost the unofficial councilor number thirteen."
"Let me guess." Izuku cuts in. "Mind control." It's the only way that he can imagine a global conspiracy to actually work without being quickly outed. Superhero comic knowledge for the win.
"Why yes, that's exactly what happened." Nedzu replies. "Nothing particularly 'crazy', for the record. Yoichi constructed a proper artificial quirk, every councilor got a copy, and suddenly their parts of the world moved according to their will. No one was turned into a puppet, but a few dozen people deemed as 'crucial' in every country, say cabinet members, heads of major newspapers, army commanders and so on, in certain situations did what the Council wanted. Being unaware of the manipulation and otherwise free to act as they pleased."
"I assume…" Izuku says. "... that it didn't work."
"It's basically the old Plato versus Aristotle debate, who knows what episode." Nedzu sighs. "The human inability to learn your own history is going to be your undoing. Plato in his political writings imagined a utopian society that could be achieved by establishing a proper political system and ensuring that people eventually fit in, by education from the youngest age and so on. Aristotle decided that it wasn't a good idea, because human society is best left to evolve on its own, typically towards the better systems with some hiccups on the way, because trying to engineer it tends to end badly. The systems are always going to be as perfect as their creators, and no human is perfect. Every system was inherently flawed, but the flaws were typically smoothed out to a passable degree as time passed, a process that trying to set up a system from scratch simply resetted. One of his compatriots, who happened to come from Eastern Europe and was born soon after communism ended, summarized this with a local saying 'socialism is a system known for bravely tackling issues unknown in other systems'. The system that the Council was trying to establish hit the same issue."
"I can imagine what side of that debacle the Council members identified with." Izuku says dryly. It's really obvious.
"Plato, yes." Nedzu replies. "If you dig deep enough in the political foundation of any totalitarian regime, you'll find his grave. Councilors had honest intentions, but the world just didn't want to cooperate. The social campaigns led nowhere, the CEOs they manipulated couldn't do what they wanted them to do because of something called laws, and changing the laws is hard when you can't mind control the entire legislature. Plus, a moment later you might discover that the law you made was faulty, so the entire cabinet you had under your thumb ends up being voted out of their office in the next election, and your whole work was for naught. Basically speaking, the Council discovered something called 'real life'."
"So, they had control… but failed in 'educating' the general population and making sure that they could follow their enlightened rule." Izuku replies. "And then, wait, I'm going to leverage my superhero genre knowledge now… a radicalisation and in-fighting started."
"Precisely." Nedzu replies. "Yoichi was the first to realize that it was going nowhere. Aristotle was back from the grave, out for vengeance. Yoichi realized that they can't force Mankind to grow up. It's like telling a twelve year old child that he's supposed to grow up and expect to see him drive his own car to his own job tomorrow morning. That's a quote from Yoichi."
"Finally, a voice of reason." Izuku replies dryly. A bit too late to avoid disaster, but…
"Yes." Nedzu agrees with him. Izuku is vaguely concerned about the mad rat agreeing with him. "He wanted the Council to switch from a secret world ruling committee to Mankind's watchdogs. By his own argument, yes, there are sweatshops in Asia where people work for unjust wages, there are groups discriminated against even in the supposedly 'most civilized' parts of the world. But there was a time when all or almost all countries in the world had their economy based on slavery, yet it was a distant past now. Simply because Mankind has managed to mostly grow out of this phase, partially on moral grounds and partially because slavery stopped being profitable due to technological progress. They needed no secret world ruling council with mind controlling superpower to achieve that, they just needed time."
"And he proposed to become… watchdogs, was it?" Izuku asks. "Wait, let me guess it… world peace?"
"Yes." Nedzu agrees. "You're catching up quickly. Yoichi saw the world and said, hey, we have people in every government. Why not make sure that no wars are happening and that the economy runs more or less smoothly? We can totally do that, let people grow as humans at their own pace, let the countries start spending less on tanks and more on education, something that should come naturally when we'll make sure that there are less political tensions in the world. Take better education, add less poverty driving people into looking for those responsible for their woes, and suddenly problems start going away. Sure, it'd take at least a century to get anywhere, but it's not like we're' making any progress with trying to rewrite legal systems and economies from the backseat.'"
"And let me guess, they hated him." Izuku says. "Because he was telling them the truth."
"I'd say that the opinions were mixed." Nedzu replies. "Yoichi tried to explain to a gremium of semi-omnipotent idealists that their ideals are unfeasible, you can imagine how well that worked out for him. There was a split between those that wanted to listen to him, and those that didn't… including his brother. The latter group having a significant numerical superiority. Unfortunately…" Nedzu pauses for a second before continuing. "Facing problems made Hisashi's faction more radical."
"I have a feeling that I'm going to regret asking that question." Izuku replies. "But how exactly do you get more radical than that?"
"By attempting to double down on the mind-control part and expand the list of controlled people tenfold if not more." Nedzu replies. Oh, yes, that works. "It was at this point that Yoichi had enough. His brother couldn't listen to reason, so Yoichi decided to run the Council into the ground. Especially as, well. Power corrupts, absolute power corrupts absolutely."
Izuku can imagine that. The ability to overthrow governments at their leisure? Who wouldn't be corrupted by that, eventually? The 'honest intentions' declining into who knows what was probably a matter of time.
"Yoichi and his Moderates struck against Hisashi's Radicals in three different ways." Nedzu replies. "The first one… well, I'll let you figure it out yourself. Clues: Riddler and Joker. Syndrome." Nedzu pauses for a moment. "C'mon, Midoriya-kun I trust your knowledge about the genre that we're all heading into as a world."
It takes Izuku ten seconds to connect the dots.
"Batman movie from 2022." Izuku says. "One of the last scenes. Joker tells Riddler a riddle from his cell. What is less valuable the more of it you have, the answer being friends. As for Syndrome…" He inhales deeply. "... 'with everyone super, no one will be."
"Precisely, Midoriya-kun." Nedzu replies. "Full marks. Hisashi discovered too late that Yoichi used all those labs that the Council provided him with to cook up a DNA-altering retrovirus, one tailored to deactivate Minus-Ultra genes of everyone infected and set for multiple transmission vectors, from droplet transmission to, imagine that, being spread around by rats." Nedzu seems to be vaguely enjoying the irony, Izuku decides. "At a scheduled date, Moderates spread the virus at major transit hubs worldwide. With almost no discernible symptoms, aside from rare cases resembling a common cold, the world missed out that particular pandemic. Today there are no genetically quirkless humans left, maybe aside from extremely isolated communities. In an instant, the Council's monopoly on quirks was shattered. Eventually, the world was going to find out. And how long can you maintain the mind-control of the world' leaders when the police and secret services will start actively looking for signs of mind-control?"
"Not for long." Izuku replies. "But wait, couldn't the Council try to reverse the process? They would just have to quarantine themselves to avoid being infected by their counter-virus, right?"
"Theoretically, yes." Nedzu nods. "Practically, no. Minus-Ultra gene inactivation is irreversible. For some reason, trying to reactivate the genes results in the subject dying quickly, even if they didn't manifest any quirk. Yoichi most likely knew why it worked that way, but he took that secret to the grave. On the day of his rebellion, he had the Moderates blow up laboratories, destroy the research data, and even execute the scientists that sided with the Radicals. Doctor Garaki and his laboratory was composed of all that was left of the Council' research wing after this, tasked with finding a cure for Yoichi's virus before the world becomes aware of the meta-abilities, something that the Council was supposed to focus on delaying for as long as possible. The moment I killed him and converted the facilities into the MLA recruitment facility, their chances of success went up in flames."
"I see." Izuku, honestly, would like to know what to say now. "Doesn't that basically mean that the Quirk Singularity is inevitable now?"
"Most likely it does." Nedzu admits. "Yoichi traded imminent and immutable totalitarian dystopia for a potential threat to the world around three to four centuries in the future. Yoichi argued that when the situation starts getting worse and worse, the world's scientists will put their heads together and will figure something out. A quirk-erasing drug, for example, to erase the quirks approaching the Quirk Singularity? Something of a quirk-suppressant to stop the quirk build-up and stabilize the phenomenon on a manageable level?"
"That sounds like making the future of the world rely on luck." Izuku replies. "Did he at least…"
"He looked into the subject himself, yes. But failed." Nedzu replies. "I looked into the subject myself and thus far failed as well. Perhaps Yoichi is right to trust in the world of the future, or maybe we're just missing something? Maybe the answer requires a particular quirk to be analyzed, one whose user wasn't born yet or simply avoided our attention thus far? I intend to find out how it'll play out in due time. Maybe even help with that? Mankind avoiding the Singularity is in my interest, after all. "
As if we'll let you live that long, Izuku thinks.
"What was the second way?" He says instead.
"No conspiracy, even one with mind control abilities, can exist in a state of chaos." Nedzu replies. "Yoichi knew that the Council's grip was strong enough to prevent the war from escalating too much, so the chances of nuclear exchange were basically zero from the start. However, once the Moderates staged a few provocations, the governments were pushed into it by popular demand."
"You mean…" Midoriya's eyes shot wide. "...he started the Third World War?!"
"Yes, indeed, Midoriya-kun." Nedzu replies, Midoriya staring at him in shock "I truly admire that man's dedication and readiness to see the world burn if it meant denying the Council the chance of decline any further into a mind-control based worldwide totalitarian regime. The war left the Council scattered. Several seats were emptied, with no way of replacing those that were lost due to the technology to create artificial quirks being lost to the world thanks to Yoichi. A fact that left a significant part of the world free of the Council's mind control. Dozens of facilities and major members became collateral damage, tens of thousands of the Council's members abandoning its ranks and hiding in the countryside, pretending that they were never a part of it. The Council is basically collapsing as we speak, despite Hisashi's attempt to keep it going. Especially as some Moderate cells are still operating even today, a fact that the assassination of Commissioner General Toyoda, a major Council member, is a solid proof of."
"That was… oh." Izuku decides that this is all EXTREMELY above his paygrade. He's relaying all of that to Commissioner Aizawa and Principal Sasaki and letting them sort the whole mess out. "Okay, what was the third way?"
"What do you think…" Nedzu asks. "... is the quirk that Yoichi created for the council members?"
"Mind control?" Izuku asks. It was mentioned, so…
"That too." Nedzu replies. "The true quirk that each of the Twelve got was the ability to take the quirks of others for themselves… or to give them out to, honestly, anyone without a Minus-Ultra gene."
Midoriya lets out a faint choking sound.
"Terrifying, even I see that." Nedzu admits. "I would rather die to your hand here and now than to have my quirk stolen and return to the status of a thoughtless animal. There is a reason why I consider the Council to be my personal enemy." That… Izuku can understand. "Thankfully, all but the councilor number one, Hisashi Shigaraki himself, got an inferior version that can only hold several quirks, while keeping two or three active at once. Including the mind-control one, that has to be kept active at all time or the links it established to its victims would be undone.. Hisashi, well, his quirk is still growing in strength. But eventually, we'll be talking about a few hundred quirks, and at least a dozen of them active at once."
"That's… disastrous." Izuku realizes. "If he actually trains those, gets the right quirks for some synergic effect, he'll…"
"... become a nightmare, yes." Nedzu replies. "Yoichi always regretted creating that quirk. Too much power for a single man, but he realized it way too late for it to matter. Hisashi, in the meantime, hated the fact that he owed it to his brother after Yoichi's rebellion. For some reason, I have a feeling that this particular part of the story will drop out of the legend that those two will eventually become." There is something of a mechanical laughter. Izuku is almost certain that Nedzu isn't actually capable of laughter, merely pretending. "You see, I still remember the arguments those two had in the laboratory, Yoichi mocking Hisashi's entire political agenda as 'All for One', while it should be 'One for All."
"How's that import…"
"Because he decided to create a counter-quirk to All for One." Nedzu cuts in. "That he named One for All. He also decided to be a little shit about it, and make his brother implicit in the process, purely for the sake of irony. Honestly, he was almost fifty years old by then, but still reading superhero comics and videocalling the Council with a decent render of himself as a, what, twenty-something guy? Rather odd two-leg, I must say."
Izuku decides to ignore the outburst.
"He gave himself an invisible quirk." Nedzu replies. "His final and most perfect creation. A meta-quirk that could be transferred from one person to another, but only when its holder truly and genuinely wished to give up the power that they had. Just a small DNA transfer, might be a hair, a bit of blood, even a sperm… and a genuine intention to transfer the quirk with it and voila. Except, that's all that it could do on its own."
"On its own?" Izuku cuts in. "Wait, it's a metaquirk, you said? Does it influence other quirks then?"
"Close, Midoriya-kun, close!" Nedzu replies. "Yoichi, as stated, was what you humans refer to as 'little shit'. He couldn't create a more complicated quirk, but… it was a meta-quirk, as you said. So, he leveraged his genetic disorder that left him increasingly weak and, eventually, wheelchair-bound. He manipulated Hisashi into using his 'All for One' to grant him a power-stockpiling quirk that was supposed to preserve his failing physical strength to let him regain his mobility. Except, it merged with the transfer quirk, exactly as Yoichi intended, creating One for All."
"A transferable stockpile quirk." Izuku realizes. "Each and every subsequent holder becoming stronger, just to match Hisashi's potential strength growth, especially if he managed to obtain an immortality quirk. A quirk that, in its core, requires selflessness of its users to avoid dying out."
It didn't matter how powerful you were. Eventually, you were going to die. One for All sounded like making its Holder think of the future and willingly preparing their successors (thus, at the very least, connecting emotionally to someone) before giving out their power willingly was a part of the design.
It probably was. If you were going to hold onto it, refusing to give it to someone else once you were out of your prime, you were going to die. Of natural causes, for example.
"That was the core idea, indeed." Nedzu admits. "Yoichi knew that even with One for All, his broken body simply couldn't withstand it, he couldn't fight his brother on his own. So he secretly transferred it to the person he trusted the most, before blowing himself up together with the henchmen that his brother sent to arrest him. After telling them to wait for some time, see how the Council's situation would develop in the aftermath of the Moderates' rebellion and then give it to someone of a sufficiently heroic heart. Someone who would use that power for the right cause."
"Does that person still have it?" Izuku asks.
"No, I believe they have already given it away." Nedzu replies calmly. "In fact, I'm entirely certain of that. Took them a while to decide on what to do with it… but eventually she has given One for All to the child she had with Yoichi. A bit nepostic, but perhaps she simply knew her kid best and was ready to trust them with the responsibility?"
"Whose the child?" Izuku asks. That's EXTREMELY important, he isn't sure how much power is in One for All right now, but if it's strong enough to oppose someone like Hisashi, they'll have to…
"It's you, Midoriya-kun." Nedzu replies. "You didn't think that Ignition was a natural part of your quirk, now did you?"
(***)
... not exactly how the world remembered the tale. But it certainly explains how Yoichi knew that giving his blood/other fluids/hair for someone else to consume would grant them his quirk. Because, between us, I have ZERO idea whatsoever how did the canon Yoichi discovered this. A fact that canon itself its ignoring. Like, HOW?
Also, surprise. Overhaul's existence - and what he was doing to Eri - was the key to survival of Mankind. Which, basically, makes Eri as something akin to a destined saviour of Mankind (if only she got a bit less maniacal 'scientific handler', ehh, a man can dream).
Also Nedzu's nervous reaction in Ties that Bind to Inko admitting (post-USJ) that Overhaul was - successfully - working on quirk erasing drugs was probably not because of the threat of such drug being in the hands of the bad guys, just saying. Probably explains why he was alright with putting Eri with her whole family on the school grounds after Kamino, hmm? Puts things in perspective.
Oh, and please. PLEASE. I was foreshadowing the 'Ignition = One for All' heavily. Green discharges when activated, supercharge of quirks, Izuku's father being described as 'heroic', Izuku having a genetic disorder (that he might have inherited) making his body progressively weaker (something that a 'strength stockpiling' quirk could counteract), Overhaul noticing how Izuku's quirk isn't behaving like it should during Aldera... the clues were all there.