This was... probably going as well as Nezu could have hoped it would.
No one had attacked anyone physically, even if Izuku looked like he was close to stabbing Yagi, and everyone else in the room bar himself and Haruki-San if he was being honest.
Not that he could blame his friend.
Quirk-based misinformation was atrocious due to All For One's repeated meddling, and Izuku, as an expert, had every right to be volatile when people did not seem to understand the very basics of this.
Quirks mixing?
Even if he were not well-read in the subject, Nezu would understand from basic biology that Quirks would not work that way; the child's quirk would resemble the parents but not be the two 'melded' together.
That being said, he still needed a minute to smooth over his ruffled feeling over how All For One tried to take Aizawa from him and did take another of his students.
From his first class.
His first kits.
If he had not already been willing to kill All For One before then Nezu was even more ready to tear into the man's flesh himself in person after learning this.
He would never let that man get away with harming his kits.
But that was a matter for a different day, right now he was refilling cups of tea in the hopes of soothing some of Izuku's nerves with some caffeine, since that seemed to calm the boy's anxiety most of the time.
Izuku shot him a thankful glance and he set the Play-Doh he was mixing down to take a sip from his cup, and unlike how the other humans would light up once they got some caffeine in, it would take at least a minute from what Izuku told him.
Nezu glanced at the other members of the room.
Shuzenji still had her lips pursed and was likely thinking over the medical problems that Izuku was trying to explain and clearly disliking it.
Tsukauchi was concerned as he sat next to Yagi and was not sure what he should do to comfort his friend.
Torino was grumbling aloud, complaining about the 'science crap' Izuku said.
Sir was stood in his corner and thinking heavily on something, Nezu however hardly paid him much attention, he lost his care when he needled Izuku about working with All For One when evidence to the contrary was provided.
Haruki-San was sitting next to Izuku watching on like he was and Yagi, Yagi still looked to be trying to understand what Izuku had just explained to them.
Nezu let his tail wag some more with his irritability with what he just learned, not that he could blame Izuku for keeping this so close to his chest, he kept his students' information under remarkably close wraps.
"Now that we've all had a moment to think things over, would anyone like to further discuss the matter of finding a successor for, One For All?" Nezu inquired, the previous name not rolling off his tongue so well.
Bias as it was, Izuku's moniker 'Inheritance' was much nicer and better fitting for the quirk all things considered.
"I… I'm still having trouble wrapping my head around all of this." Yagi admitted not having any of the confidence typical of the man when he was in costume.
Nezu would at least give him some credit for saying it.
Izuku rubbed a pair of his fingers to his forehead but did not sigh this time.
"I can explain your quirk in a flat layman's term if you'd like Yagi?" Izuku offered tired but less willing to stab.
Yagi ducked his head and swallowed thickly "If you could, I would appreciate young Midoriya."
Izuku furrowed his brows "Dr. Midoriya." Izuku corrected, perhaps a bit spiteful since Nezu had never heard Izuku insisted for anyone else to call him doctor from what he could recall, even if he was technically a doctor of quirk science.
"To start from the beginning," Izuku spoke placing down his cup and grabbing the magnets pulling one off "The brother's quirk, which I'll call Inheritance from this point on, since it perfectly describes what his quirk does and how it actually works." Izuku explained, showing the green piece in his hand.
Yagi's nose scrunched up at the name, clearly not used to the name either.
"Inheritance was a quirk collector that could only gather more quirks by being passed on to another person, by some form of ingesting DNA, right?" Izuku guessed.
"Yes, that is how the quirk is passed on." Torino commented "Shimura got it from her predecessor's blood and gave it to Yagi through a piece of hair." Torino added jabbing a thumb at Yagi.
"As I thought," Izuku muttered before biting his tongue to keep from rambling on about that, but Nezu would be sure to ask him about it later.
"Well, that's all that Inheritance would have been if All For One hadn't place the strength gathering quirk in him, one I'm not sure the specifics of just yet beyond that it was probably an invisible quirk that has to be passed on to work since it doesn't lose power with each new person." Izuku told them rambling a bit but quickly moved on.
"By adding that strength quirk he made the growing collection much stronger early on, with each person's quirk being added with the strength growing with each time it was passed," Izuku elaborated as he placed more magnets onto the first one.
"Now there is currently a grand total of eight quirks which you now carry and can use at any time." Izuku explained placing the multiple magnets down.
"But the strength quirk is the only one I can use." Yagi pointed out and Izuku raised an eye back at him.
"Have you tried to use anyone else's? If you can use the strength one that you're seven generations removed from than you can use any of the previous user's quirks." Izuku said in response.
Yagi's mouth opened then closed "Well, no." Yagi confessed flustered "B-but wouldn't I have used one of the others by accident by now?" Yagi countered and with a reasonable reply since Izuku hummed back.
"You really haven't? Maybe it's an incompatibility causing the problem? Without a baseline quirk to work with you might not be able to fully connect to the collection of quirks, have you asked the past holders about this? Or are you the first quirkless wielder?" Izuku questioned rubbing his chin.
That made Yagi look like he had been slapped for some reason, but Torino scoffed at the question.
"Afraid we don't know; Shimura didn't talk about the quirk much and I certainly hadn't asked about the past holders when she was still alive." Torino informed them all.
"No, no I mean have you asked the remnants of the past holders in Inheritance, surely you'd talked with them at least once over all of the years you've had the quirk Yagi." Izuku insisted and then it was Nezu's turn to look towards Izuku.
There was a silence.
"You... haven't talked to them? You might really be disconnected from the rest of the quirks then, huh." Izuku stated, turning more thoughtful as he considered that.
"What remnants are you talking about?" Tsukauchi asked tentatively.
"Oh, right." Izuku said realizing that he had not spoken about this before now and lightly hitting his forehead.
"I only learned of this phenomenon because of Kurogiri, but when a quirk is passed on it carries over a… fragment of sorts, of the person it was from. It can be small like a few out of place memories or a skill you've never had before." Izuku informed them.
"However, a quirk can have the whole person in the form of, well for the lack of a better term, a subconscious ghost." Izuku said and Yagi's eyes nearly doubled in size.
"A ghost?" Yagi whispered disbelievingly.
"Yes, an echo of the person can be imprinted onto the quirk, and you can interact with them mentally, have you ever had a person repeated appear in your dreams or been hearing voices?" Izuku threw out there.
And Yagi, well he began crying again and frankly he looked much more of a wreck than from the Tenko reveal.
He hunched in on himself and covered his mouth with both of his hands.
"Oi, what's the matter with you, you Zygote?" Torino questioned, not catching on just yet.
"Nana... " Yagi whispered and the tears fell even harder as his body began to tremble.
"Toshinori," Tsukauchi said sadly as he placed a hand on Yagi's back, the blonde not ripping himself away this time.
Ah.
Nezu could not help feeling sympathy pains for the man.
He would not know how he would react if he had someone tell him he was hearing a believed to be lost loved one in his head and after previously believing he was crazy for hearing their voice.
"Apologizes Yagi, I understand that this is probably a big realization for you, if you need a moment to-" Izuku apologized but Yagi held a hand up.
The man was shaking still, he took a deep breath before he raised his head "How... how aware would these… vestiges be?" Yagi hoarsely asked.
"Well, it depends on how strong the fragment is. If it's just a few memories, they wouldn't be sentient but if you're hearing voices or seeing them in dreams then there's a good chance, they are fully aware and can learn new things." Izuku answered.
"Then I can… speak with her again?" Yagi pressed.
"Yes, though be aware that the 'vestige' of her memory of her own life would stop at the moment of when the quirk was passed on to you, everything after that would be supplemented by your own memories." Izuku elaborated for the man.
"Could I speak to them outside of sleep?" Yagi asked.
"Unfortunately, I don't know, Inheritance hasn't been studied and I can't tell you much about the specifics, only guesses from what Kurogiri's own limited understanding of All For One's experiments." Izuku admitted.
"Yes, yes of course." Yagi muttered, disappointed but resigned.
"Is knowing this making you reconsider passing your quirk on?" Haruki-San asked, a reasonable question since this fact would give anyone pause.
"I… I'll still pass One For All on, I cannot afford not to do so, but I believe I shall view the rest of my time with it differently." Yagi responded.
"Have you thought about what person you will be looking for as a successor?" Nezu inquired, though he and Izuku had talked about in a passing fashion, more of a thought experiment than anything else, they would still need Yagi's consent to pass Inheritance on.
"I've put some thought into it, though I was hoping to get your advice on where to look for a successor." Yagi confessed a hand reaching up to rub the back of his neck again.
"Oh, please do enlighten me." Nezu insisted, waving for him to continue.
"Ah, well I believe that finding someone of the right mind set would be greatly important." Yagi answered, "There is an array of different personalities in heroics, but I think having someone that is more optimistic would be best as the next successor." Yagi elaborated further.
Nezu toyed with the thought.
While there was the risk of the person chosen being crushed to learn such a thing if they did have a happier outlook, it would more of a boon than a con.
Giving outrageous physical power to a more negative mindset or even a logical person might be more dangerous, since a good chunk of those people could just as easily turn around and become another problem if they decided to use that power irresponsibly.
And that was before taking the other quirks they could use into account as well.
"I can agree with that, finding someone with the right mindset about heroics will be important, there are probably more than a couple people out there that we can physically give the quirk without it killing them, but that won't matter much if they have a mental break down before they can get ahold of the quirk." Izuku said crossing his arms and leaning back against the couch.
"Unfortunately, that would severely limit our candidate pool," Izuku commented letting his head fall to the side.
"And they would need to be reasonably fit, all known strength quirks rely on a baseline of muscle to reinforce the body and pump full of power." Nezu added making Izuku sigh.
"Which would effectively exclude almost all of the quirkless in Japan, what with how they're treated and their living situations." Izuku pointed out and Nezu was almost tempted to lower his ears.
"Well, what about you Brat?" Torino asked and Izuku blinked.
"... Pardon?" Izuku muttered.
"You might not have the sunny disposition kid but you're quirkless, in better shape than the Zygote was when he got it, and you'd have a better way to defend yourself when the bastard comes calling if you were the successor." Torino stated.
Nezu's mind when to work with the idea.
As an expert in quirk science Izuku would have a much better time managing the new quirks in a way that would be healthy, not to mention that Izuku was already a target and there was a chance that All For One would not think that he would be the wielder.
The only true downside might be the discovery that Izuku 'did' have a quirk, though there would be ways to suppress the quirks and keep him, seemingly, a two-toes still.
"You can't be serious? You cannot really be considering giving that boy One For All!" Sasaki said after being silent for nearly the whole conversation.
Nezu dismissed the man, it would be a reasonable path given the circumstances no matter what protests Sasaki could think up-
"No."
Outtakes with the past holders prt3
Having just finished calming down Nana after the reveal of Tenko being alive.
Bruce the 3rd: For f**ks sake, what's your kid going to say next? That he knows about us too?
Izuku proceeds to explain quirk 'remnants' to everyone.
Everyone:...
Bruce the 3rd: I was f**king joking! What the f**k!?
2nd grabs Youchi by the shoulders and gets his face.
2nd: Seriously, who the hell did you sleep with!?
Youchi *flustered* : I didn't! I've never- I swear!