Alterations

"Daddy, why do I have to see the Doctor again?" Izuku asked.

Hisashi looked down at his son. Izuku was dwarfed by Gigantomachia's bulk but was holding on to his huge hand. His bodyguard was being extremely careful with his grip and the white haired man rather thought that it was more that Izuku was holding onto Gigantomachia rather than Gigantomachia holding onto Izuku.

He'd introduced Gigantomachia to Izuku a few days after Izuku's birthday. The huge man was very taken with his son and later that same day, he had checked up on them to find that Gigantomachia was sitting up against the wall with Izuku asleep on his lap. He had made it clear to the large man that in case of emergency, he was to protect Izuku.

"It's a check up before you go to school," Hisashi told him.

He didn't expect the smile that burst across Izuku's face. His green eyes were wide and happy and there were tears in the corners. He had lived with Inko for long enough to know that Izuku had inherited her tendency to cry with happiness. He would grow out of that.

Izuku began skipping with happiness.

All For One's eyes narrowed. "You don't like it here?" He asked carefully. Why else would Izuku be so happy?

"No! I love being with Daddy," Izuku said. He'd learned better now than to say that he wanted to be with Mummy as well. Hisashi thought the desire was still there but only sometimes.

However, there was a but lurking behind his son's words. Izuku might only be five years old but Hisashi could hear it. He could hear it with his associates and they had some skill at controlling themselves.

Hisashi cocked his head slightly, letting his son know he should continue.

Izuku looked uncertain.

"What is it, Izuku?" He probed.

"It's something bad, and Mummy said I shouldn't say bad things," the green haired boy replied.

"I want to know, Izuku. I want you to be happy." He decided to say nothing about Inko. There was no need to bring attention to the fact that she wasn't there.

Last he had heard, Izuku and Tomura were getting along. Well, maybe that was an exaggeration but Tomura had realised that he had to live with Izuku and they had worked out how to stay out of each other's way. At least, that's what Kurogiri had reported.

Izuku looked uncertain for a few moments more before he sighed. "It's Tomura," he whispered looking at the floor.

"He hasn't hurt you," All For One commented. He hadn't been called upon to transfer Tomura's quirk back to him and Kurogiri hadn't reported that he had to bandage Tomura's burns.

"He wants to," Izuku said as firmly as a five year old could.

"Izuku, what do you mean?"

"He wants to," his son repeated. "He's always watching. And sometimes he comes close."

"I'll talk to him," All For One promised. "But Izuku, I'll tell you what I told Tomura. There is a place for both of you," he assured his son. "I need you both."

"Why?" It was a surprisingly innocent question but Hisashi could feel the weight behind it.

"Because I need your help," he told his son. It was the truth.

The simple explanation seemed to satisfy Izuku which was just as well because Hisashi wasn't sure he'd be able to explain what exactly he needed help with in a way that a five year old would understand.

"Hello Doctor," Izuku said instead as they went through the door.

"Ah Little Izuku," Kyudai greeted them.

Hisashi took in the Doctor's appearance. The old man had made an effort to appear non-threatening. That was good.

"I'm going to school!" Izuku said happily.

"Are you now?" Doctor Garaki asked brightly.

All For One gave him an amused look at Gigantomachia squeezed into the room and took up a position by the door.

The Doctor ignored him.

"I am!"

"Then I'd better make sure you get a proper check up today," Kyudai said, before taking something from his desk. It was a small cup. "First though, could you drink this? I think you will need it today."

Hisashi cocked his head slightly.

"It's a painkiller," Garaki told him.

Ah. Hisashi understood what that was for. Before Izuku could go to school he had to have that modification done to his quirk, which was still unnamed. While Hisashi would tell Izuku that he could only use Fire Breath, if an accident happened it would be best if Izuku could correct it himself. No one was going to believe a child's crying that their quirk had been taken, if it had already been returned. Childhood glitches in quirks were common enough.

"Why do I need a painkiller?" Izuku asked as he took the small cup and looked dubiously at the liquid.

"Doctor Garaki is going to give you an injection today as well," Hisashi told his son. "It's something you need before school."

"What for?"

"Well, Izuku, I have to give you two injections today. One is your vaccinations," the Doctor explained.

Hisashi nodded. Izuku had probably missed a few with everything that had happened. With all the tests the Doctor had done, he was sure he'd checked which immunisations were active and which weren't. He paid him enough to do that sort of routine work.

"And the other is to modify your quirk."

Understandably Izuku shrank back, protectively. Kyudai looked towards him for support.

"Izuku," All For One said softly. Izuku turned to him, looking for comfort. He held out his hand and Izuku came to him. Hisashi placed his hand on Izuku's forehead, ruffling his curls. "When you go to school, you won't be able to show your quirk," he said.

"I can't?" Izuku was confused.

"You may show them Fire Breath," he clarified. "But you won't be able to use your quirk."

"Why not?"

There was a myriad of answers to that question but Hisashi reminded himself he had to go for the answer Izuku would understand, and obey, so simple was best. "I won't be around to transfer the quirks back, and I don't think your friends would like having their quirks taken."

"I wouldn't take my friend's quirks!" Izuku objected.

Hisashi wondered if Izuku realised the irony of his answer. He doubted it, so let it go for the moment. If it turned out to be a true statement, he'd deal with it then and privately laugh, even as he cleaned up the mess it would no doubt cause.

"That's what this injection is for," Hisashi continued. "It will allow you to give back quirks."

Izuku's eyes went wide at that. "You mean like yours?" he asked immediately.

"Exactly like that."

His son grinned before he frowned. It was a rather adorable expression over his freckles. "If I can give back quirks, then why can't I show mine?"

Darn. All For One had hoped Izuku wouldn't make that connection yet but it was just a small annoyance and he was more proud than he was annoyed. The question proved Izuku's intelligence.

"Izuku, Tomura doesn't like it when you take his quirk, does he?" Hisashi asked.

Izuku shook his head. "He doesn't."

"Do you think other people would like it?"

"No," Izuku said firmly.

"Then it would be best if you don't show them your quirk. Your quirk can be our secret."

Green eyes widened slightly but then Izuku smiled and nodded. "Our secret," he whispered, ignoring the fact that the Doctor and Gigantomachia were in the room.

Izuku turned around to face Kyudai again. It was a good indication that he was ready.

"Please drink your medicine," Doctor Garaki reminded Izuku before he reached out to take the small cup once Izuku had downed the liquid.

"Before we begin, Hisashi could you give me an assessment of Izuku's quirk?" Garaki asked, looking at him.

He knew what that meant and activated All For One while looking at Izuku. His quirk glowed but Hisashi felt his eyes widen slightly when he realised there was no other quirk visible.

"That is answer enough," Doctor Garaki murmured and wrote a few things down. "Is there any visible change?"

"No," All For One told the other man. To his vision Izuku's version of All For One still glowed green to his senses. The colour hadn't changed with the addition of Fire Breath but maybe that green glow was slightly larger? That could have to do with Izuku simply getting older though. He would have to watch further and make assessments. Garaki was not the only one who could run experiments.

"Then it's time for this," Kyudai said. He pulled out a bottle and a small ball of cotton wool. Deftly he applied the contents of the bottle to the cotton wool and gently wiped down Izuku's arm. There was the sharp smell of alcohol.

Doctor Garaki picked up the first needle and gave Izuku the injection. "That's your vaccination," he told All For One's son. "Now the next shot," he added, picking up the second needle. "This one could sting Izuku, so I want you to spend the rest of the day in bed."

Izuku looked frightened again. Garaki earned his pay by reacting as a normal doctor should. "It's nothing to be worried about, little one," he said quickly. "Just a precaution."

Green hair flopped as Izuku nodded though there was a trace of uncertainty in the movement. Kyudai didn't care about that, not really, and there was only so long he could hold the act. He took Izuku's arm and pulled out another needle. This was one Hisashi recognised for taking blood and he looked at it in askance.

"This is an intravenous injection," Doctor Garaki told him. "Hold still Izuku," he instructed as he brought the needle to Izuku's elbow. While many doctors would struggle to find a vein, Kyudai had kept up his skills. He ran his own experiments, so of course he retained his practical skills so he quickly found a vein in Izuku's arm. The needle was quickly inserted and then the larger syringe attached to it. With a surprisingly gentle touch, Kyudai depressed the plunger, emptying the significantly larger dose into Izuku's arm.

After the needle was withdrawn, Izuku slapped his hand over the spot.

"It hurts," he said, a little quaver in his voice.

"A lot?" Hisashi asked.

Izuku shook his head.

Kyudai looked at him. "It will sting but I've customised the dose for Izuku, so that should be all it does," came the information.

Hisashi nodded. "How long will it take?"

"An hour or two at the most," Garaki told him. "Blood circulates quickly so it should readily impact Izuku's quirk factor."

That decided Hisashi and he pulled at one of the many quirks he had. It was another of those that were considered useless by their former owners. They had uses for him, and All For One was quick to step forward when Izuku's eyes closed. Force Sleep was useful for capturing some of his enemies but it had other uses, especially now.

He picked up Izuku and held him before sitting back in the chair Kyudai had put out earlier. Hisashi smiled down at his son. Asleep, Izuku was so peaceful.

It was only a moment. There were still things to discuss with Garaki.

"I will need a quirk registration certificate for Izuku, under the name-" All For One paused slightly. He'd promised Tomura he wouldn't register Izuku as a Shigaraki but he also couldn't register him as Midoriya. While the Police search for Izuku and himself was going nowhere, there was no need to be sloppy. "Go under the name Izuku Chui," he decided.

Garaki gave him a look but didn't question it as he wrote down the name. He'd have the paperwork ready for Izuku's enrollment.

"How is your research?" All For One asked. Izuku wasn't the only thing Kyudai had been working on.

"Well, but single alterations are relatively easy," Kyudai reminded him. "Multiple, compounding alterations are far more difficult."

"I am aware of this," Hisashi replied mildly. It was why he continued to pay Garaki. He didn't need the second best quirk expert on the planet, he needed the best. And the one with the most practical experience. Garaki knew that as well and made sure he remained relevant.

Kyudai shook his head. "The rest of the world does not believe the type of quirk modification you want is possible. They would never believe that Izuku has had an aspect added to his quirk."

"We still need a name for it," he said softly, indicating his acceptance of Garaki's rebuke.

"I prefer Singularity," the Doctor replied immediately.

"That is somewhat ostentatious," Hisashi commented.

"All For One II might be a bit confusing," Kyudai said.

"Doctor," there was a warning note in Hisashi's voice.

"It's accurate now," he objected.

That was true. Or rather, it would when Izuku woke up.

"Expropriate?" Hisashi murmured the idea but knew it sounded too much like a villain's quirk. Not that he cared about that, but it was best not to be obvious.

"Assimilate?" Kyudai countered.

Hisashi sighed and carefully waved one hand. "It can wait," he decided before he switched subjects. "Make a prototype," he instructed. "Something small as a proof of concept. Give it a warp quirk," he added.

Garaki's eyes widened. He knew exactly where that warp quirk was coming from. Kurogiri had the most viable warp quirk but there were others. He nodded. "It will take a few months," he said as he thought about the task. "I could make something faster, but it would be temporary."

"Yes," All For One agreed. "It should be a robust prototype."

He rose, still carrying Izuku. "I'll need the paper's tomorrow," he said by way of parting.

Kyudai nodded and turned back to his desk as All For One left, Gigantomachia following in his wake. Hisashi looked down at his son, who was still sleeping.

This had been a productive day.