Not Brothers

"Tomura."

The boy looked up at him as he waved Kurogiri away. Gold eyes were confused.

"What happened last night?" Hisashi asked. Izuku had told him what happened but beyond 'Tomura tried to use his quirk on me' it wasn't worth attempting to get details out of an almost five year old. Besides, he'd promised he would talk to Tomura today and if he didn't, the boy would have thrown some sort of tantrum. Not that it would bother him but if he tried to hurt Izuku again, then Izuku would again take his quirk. And then they'd be back to where they were last night.

He really couldn't blame his son for that action and should perhaps look into finding Izuku a quirk he could use to counter Tomura's other than his version of All For One.

"He was being stupid," Tomura snapped. After a few years of encouragement, the boy was much more confident when speaking with him.

"How?" All For One probed, already knowing the answer would be something about heroes.

Tomura huffed. "He kept blathering on about how he was going to be a hero with his quirk! It was annoying."

If there was one singular thing that impressed Hisashi about Tomura it was that the boy had no fear. He knew Izuku was his son. He knew that he at least cared a little for Izuku but he was still prepared to attack Izuku with his quirk! Most would call it stupid and while it could definitely be argued that at Tomura's age, he should know there were consequences to his actions, All For One saw something more. There was a spark in the boy, something he could use and nurture.

And even if it turned out that the spark snuffed out in his teenage years, Tomura had other uses. Tenko Shimura was a name that had potential, if used at the right time. Tomura, would either grow to be his lieutenant, or would be a throw away line at an opportune time.

Besides, Izuku was smart enough not to let Tomura hurt him and had figured out how to protect himself. Usually emitter type quirks were the easiest for Izuku to take but the threat of disintegration had meant that Izuku had worked out how to take Tomura's quickly enough. And Tomura hadn't yet truly realised that he was strong enough and big enough to hurt Izuku in other ways. Tomura always went for his quirk first which was why he was bound to transfer it back.

"Izuku is still young," Hisashi said. He couldn't claim to know that Tomura had gone through a hero phase, but he imagined the boy had, back when he was still Tenko.

"Heroes are stupid," Tomura objected.

"They are," All For One agreed. "But do you know why I brought Izuku here?" He'd told Kurogiri but he was pretty sure the Warp Gate hadn't told Tomura.

"No." The reply was sullen.

All For One smiled at Tomura. Getting loyalty from children relied on encouraging them but also providing some boundaries and goals. He'd encouraged Tomura since he found him, and had Kurogiri provide some boundaries. Not many, the same as Izuku wouldn't have many boundaries so long as he was loyal. For Tomura it was now time to start introducing some goals.

"You will, when you are older, support me," he stated clearly.

The boy's face soured. Not greatly but enough for Hisashi to know there was an issue. All For One didn't let his smile waver. "There's not that many player characters I can trust," he added in a whisper. "And when you support me, I will support you on your quests."

That soothed Tomura slightly. "I will not be the party leader forever," All For One continued. He would be but if things worked out Tomura would have enough autonomy that he'd believe himself his own leader, and that he had just been the guiding mentor at the beginning of the quest.

"And what of Izuku, Sensei?" The golden eyed boy demanded.

Hisashi made sure he was looking into Tomura's eyes. "Izuku will support me as well," he told the other boy. Oh, Izuku would support him and if things went well, Izuku would know far more about his operations than Tomura.

He'd learned during the first war that it was best to have multiple plans and to keep making multiple plans, even those plans that conflicted with each other. Things didn't just miraculously work out without a lot of work. Tomura was one such plan. He would be a visible villain for the Heroes to fight.

That was the other thing he'd learned over time. Sometimes it was easier to do what you wanted if you gave your enemies exactly what they expected. That buffoon All Might, and Heroes in general expected flashy villains. Tomura would be that. That was one of the reasons he'd assigned Kurogiri to Tomura, not Izuku. For Tomura to be effective, he'd have to have someone skilled on his side initially. Kurogiri would be that one, at least until Tomura's usefulness was over.

"Will he be in my party?" Tomura asked.

"Only as support," Hisashi replied with a smile. Izuku would only be in Tomura's party to report back, or to learn something. His son's primary role would be to support him, and him alone. He wouldn't accept anything else.

"He better not be an NPC."

"I think you will find that when he's older, his support will be valuable."

"Not if he wants to be a hero."

Ah, they were back to that. All For One grinned, reaching out to ruffle Tomura's hair. The boy didn't like to be touched, but at the same time he craved feeling and Hisashi had learned to use that desire. "Even a hero can be useful," he told the young boy but didn't explain.

Some things Tomura had to work out for himself.

-ted-

"What is it, Doctor?" Hisashi looked at the screen showing Dr Garaki.

"I've completed the analysis, Hisashi," the old man replied.

Hisashi nodded. That wasn't his name but he found himself getting used to it so it would do, for the moment. Eventually Hisashi Midoriya would die, and he'd take a new name. Not that he needed a name very often. Most of the Underworld knew him by reputation or simply called him Sensei. Those few that needed an actual name to use usually knew him for a different purpose.

Kyudai was in yet another group. He was a long term associate but he called him either by the name of the day or Sensei.

"What did you find?" All For One asked. Kyudai was only ever happy when he was in a lab and Hisashi usually had more than enough reason to give the Doctor a lab. There was still so much not known about Quirks and what many - very carefully controlled - laboratories were discovering now, Kyudai had learned almost 80 years ago when they first met.

"He cannot transfer quirks away from himself," the old man said. "It's actually quite fascinating!" Kyudai continued.

Hisashi knew better than to let him continue. "Does he have a capacity?" He interrupted with the question.

"No!" Kyudai actually sounded delighted at the answer, and it was something he already knew.. "At least, nothing that is obvious," the scientist continued, his eyes shining. "It is absolutely fascinating. He has the potential to be a controlled quirk singularity!"

"It's quite troublesome," All For One countered. Izuku's ability to take quirks was brilliant. The, as yet, unnamed quirk was a mix of his own and Inko Midoriya's quirk. Izuku could attract quirks from a distance. It was fantastic, but not perfect. Izuku had inherited a mix of their quirks but not all of either of them. Inko could do a bit more than simply attract small items. She could, if desired, focus on the atoms and pull them. Izuku didn't seem to have that ability. He could only take the entire quirk. Not that Hisashi thought of that as a problem but it was indicative. The merger with All For One had not been exact either. Izuku could take quirks, but could not give them. He could use them as well and he had one more feature of All For One that Hisashi thought slightly annoying. Izuku's quirk, like his, could not be taken. He'd tried. It had remained stubbornly attached to his son.

If Hisashi had been Enji Todoroki he would have been trying again, deeming Izuku a failure. It wasn't like All For One knew exactly what the Number Two Hero was doing but the birth dates of his children made it kind of obvious. The fact that Endeavor remained the Number Two Hero, despite his record, all but confirmed Hisashi's thought about his children. The Hero Public Safety Commission would overlook a lot for the sake of a strong quirk, and Japan's Emperor of the Underworld rather fancied that there were those in the Commission who were drooling at the thought of the child Endeavor wanted to produce.

Izuku though was enough success for him to work with.

"Of course! Quirk singularity is a problem," Kyudai gushed. "But there's ways around that. The Quirkless are stabilisers for modern quirks and just spreading their genes around more would postpone Quirk Singularity for generations to come!" The Doctor shrugged. He knew how likely that was, though he was slightly curious to know how long it would take before one of the mainstream labs stumbled upon that knowledge and what they'd do with it. If they hadn't already discovered that and had the knowledge suppressed. People could be so prejudiced at times.

"But Izuku could be a singularity in a matter of years!"

"I don't want a singularity," Hisashi reminded the Doctor.

"Yes, you want him to be able to transfer quirks," Kyudai replied, looking at him through the vid feed. "That's easy." The good Doctor waved one hand to dismiss the problem before he continued. "His potential as a singularity is far more interesting, as is what we could learn on the way there. He cannot give up a quirk, and by keeping them, they will merge into-"

"Transferring quirks is easy?" Hisashi interrupted. Garaki hadn't told him this before.

The Doctor seemed to refocus. "Transferring is the opposite of taking them. I'd have to reverse engineer that part of his Quirk, or I could use part of yours," the man told him.

"Part of mine?" All For One questioned. Izuku already had part of his quirk. It was the fact that he didn't have the whole quirk which was the problem. Mostly.

Kyudai was wise enough to hear the warning in his voice. "All For One allows you to take another's quirk, use it as your own, and to give it to someone else. The Re-animation Project relies on your ability to give someone more than one quirk. As such, I've studied your quirk the most out of any and have broken down all the components. I can give your son the ability to transfer quirks, though there would be a time limit on it."

All For One was silent for a few moments as he considered the words. "Why?" He asked finally. Garaki was useful but sometimes he was trying. Right now, he was being especially trying.

"Your son cannot naturally transfer quirks. If he keeps them long enough, they will merge with his own until they are his quirk and he won't be able to separate them. That's why he has the ability to become the singularity!"

That sounded suspiciously like another quirk he knew about. Not the singularity bit but the rest. It appeared Izuku might get more from him and his genes than he believed. "How long?" Hisashi asked.

"I don't know," Kyudai replied instantly. "I suspect it will differ from Quirk to Quirk and how much Izuku uses the quirk. If he uses it a lot, or in conjunction with other quirks, then it could be faster. But that's a guess, it might be the opposite, that using a quirk keeps it defined and separate from his. I will have to run tests."

All For One nodded. They would have to run tests. Nothing damaging but Izuku would probably be more than happy to oblige. He was fascinated with Quirks, especially his own and didn't get enough chances to practice with it. He'd planned to change that in future but it looked like those plans needed to be accelerated.

"This is so exciting," Dr Garaki said gleefully. "I can't wait to begin. His potential is amazing."

"And mine," Hizashi reminded the Doctor. Kyudai was good but he sometimes needed to be reminded who was in charge. "Izuku is not to be damaged so this will begin as nothing more than a check up with the family doctor."

For one split second, it looked like the Doctor might disobey but then he nodded. There was nothing sullen about the movement. Sullenness was for children. Besides, Dr Garaki was skilled enough to know how to stretch the samples he would no doubt take.

"I want to know the limits of Izuku's quirk but in such a way that he remains happy," All For One continued. Beating children did not lead into him getting good lieutenants later and that was the ultimate goal. "And work on making whatever is needed to have him able to transfer quirks as well. But I want that to be as painless as possible."

From the way Dr Garaki frowned at that, Hisashi knew that was going to be difficult. The Doctor was the leading world expert on Quirks but had never had to gain that knowledge humanely. But while humanity had become obsessed with changes from within and thus had not pursued a journey into space, that meant that some forms of genetic manipulation were almost routine. Almost, because the emergence of Quirks and knee jerk reactions once Quirked individuals came into power meant that genetic manipulation was frowned upon. In many ways, Hisashi had to thank the experiments conducted on those who first displayed quirks by others. They weren't ethical, they weren't humane, but they did contribute greatly to the knowledge of quirks that society had now. It was a shame that he'd had to kill many of them.

"RNA modification will have some pain," the Doctor indicated. He had done a lot of it in the past and his subjects… Well, for some, the less said the better, for others, they walked out of his lab completely fine, just altered but they all reported that the pain was quite excruciating. "but it can be managed with pain killers, and is only temporary," he added quickly.

Hisashi nodded. He could accept that. Izuku could be prepared for that. "How long will that take?"

"A month, but I would like to get a baseline on his natural quirk first," Kyudai indicated. "Because if he merges the ability to transfer quirks with his own, that may destroy its ability to merge a quirk." The Doctor sounded like he was in pain with that admission but Garaki had learned a long time ago never to lie to him.

"Very good. I will have Izuku sent to you tomorrow. Make the appropriate arrangements," All For One instructed before giving a nod and closing the vid link.

In the newfound silence of his office, the man currently known as Hisashi Midoriya smiled. He was pleased and he leaned back, closing his eyes. He'd wanted his and Inko's quirk to merge and if he was honest, he didn't want his child to get a perfect merger with all the abilities of both. Ideally, he wanted his child to be able to take and give quirks from a distance, and for that enhanced version of All For One to be one he could take. He had gotten some of his desire. And while it appeared he wouldn't be able to take Izuku's quirk, which really needed a name, the other deficit could be fixed and in the long term he would gain a strong follower.

That was sufficient compensation.