I will say this here and now; this is not going to be my main story until Powers you Earn is caught up with the manga. My updates on this will be sporadic, and random, so do not expect anything resembling a schedule. With that said, if Powers you Earn does catch up to the MHA storyline, then I will put that story on hiatus and work on this, or even another story. On to the story!

Izuku was in the doctor's office, Izuku was bouncing in his mother's lap with his All Might action figure in his hand. The doctor was checking over the notes before looking up.

"Well, Izuku does indeed have a quirk, though it's one of the more peculiar ones we have recorded." he confirmed before handing Inko a folder. Opening it, she found some odd pictures that showed a red liquid with glowing particles in a vial. "His body produces a bioluminescent substance in his body, mostly found in his blood, that had been able to modify genetic material."

"That sounds so cool! What's that mean?" Izuku asked, making both adults chuckle at his antics. The doctor did use big words, so he decided to clarify.

"All living things, from people to plants have what's known as DNA. It controls a lot of things about a person, from their max height, their hair and skin color, and of course, the quirk they possess. Are you with me so far kiddo?" he asked, to which Izuku nodded.

"DNA tells the body what to look like and what to do." The child responded. The quirk doctor smiled and nodded.

"That's very good! Now what your quirk does is make a special substance that glows, called bioluminescence, that can change DNA of any living thing if given a command to do so." Izuku's eyes were now wide in joy.

"So I can give myself multiple quirks!?" he asked excitedly.

"In theory, yes. Though if you want to use your quirk, I highly recommend you do so in the hospital under medical supervision and work small; you are messing with what makes you, you after all." The doctor warned. Inko thanked the good doctor before walking out of the hospital with her son.

"Hey, mom?" Izuku inquired. Inko looked down. "The doctor said messing with DNA is dangerous. Can I learn about it first?" Izuku's mother smiled and gave a kind nod. She was going to have him learn the basics first anyway, and if he was comfortable afterward, then bring him to the hospital to experiment.

It's been three months since the doctor confirmed Izuku's quirk, and the child was ready to try out his quirk. He surprisingly, or not depending on the view, was talented in learning anything that related to biology. He still had trouble with many of the big words, but decided to give them nicknames instead and continued on.

"Alright little buddy, all of the equipment is set up. You're good to go!" the nurse, named Grace, called to him. Izuku, holding his mom's hand, nodded and focused on the light inside of himself. He rarely saw it, as he didn't like being hurt, but Izuku instinctively knew how to control the 'bio-glow' to change him how he wanted. He hated being one of the shortest kids in class, so he focused on making his build taller. Feeling pain, he didn't know whether he was doing anything wrong or not, so he looked at the nurse that he was with.

"I hurt. My joints hurt. This isn't fun." he told her, and Inko bent over to hug him.

"Can you tell me how much it hurts? We can stop at any time." the nurse informed the child. Izuku shook his head no.

"It's like I played all day and I wake up not wanting to move." he tried to articulate. Inko held him tight, and Izuku hugged her in return. He didn't know changing himself hurt like this. Katsuki's explosions didn't hurt him, right?

After a while, Izuku's pain went from being very sore to a dull ache, like he had just run fast and was out of breath. He told Grace how he felt.

"Well, that's good. You'll probably hurt for a couple days until your body heals. Come back then, or if you have any sudden pains that hurt more than they did right now." she rattled off before pulling a lollipop out for Izuku, who was more than happy for it. The little boy then hugged the nurse before returning to mom.

"Thank you for your time." Inko bowed.

"It was no trouble. Keep an eye on him, and make sure he -" the nurse said before being interrupted.

"I don't hurt anymore! It's all gone!" Izuku shouted, patting his elbows and knees. Grace, getting over the initial shock that days of soreness was reduced to not even ten minutes, smiled.

"Well, if you're okay then I can supervise another change, but no more than for a few days; you need to get used to any change you make. If that is alright with you, Midoriya-san." Grace turned to Inko, who looked a little unsure.

"I trust Izuku, but I don't know what limits he has. Is it safe?" she asked. The nurse shrugged before answering.

"It's safer here than at home, that I can guarantee. Whether it's safe period, I don't know. Quirks like his are rare, and little is known about what limits he could have." she admitted. Inko looked at her son's hopeful eyes, and caved.

"At least if anything goes wrong, he'll have people to help." she assured herself, giving consent. Izuku grinned before focusing once again. The first change was aesthetic, but if he was going to be a hero, he needed to be strong like All Might. He focused on how his muscles were built, and made them denser, more compact. Soon, he felt his body feel like it was burning up.

"Un… can I get some water?" he asked, trying not to sound in pain. He was having second thoughts about how good of an idea this was, but he felt it was a bad idea to stop in the middle, so he endured. Grace quickly left and came back with more than one water bottle. Izuku took one with a raspy 'thank you' before downing half of it rather fast. His body soon felt the burning sensation lessen enough it was bearable.

"I don't wanna keep going." he mumbled as he leaned heavily on his mother. Inko assured him he didn't need to before bowing to Grace. Izuku was better after six minutes and thirty seconds, as Grace used a stopwatch this time. She told them she was updating Izuku's quirk registry, but they were only paying half an ear.

Right now, they just wanted to go home.

Izuku was having a bad day. It was a week since his first time testing his quirk at the hospital, and he had told everyone in class what his quirk was.

And Katsuki had to make fun of it.

"So you control what keeps us alive?" he accused, not understanding just what 'genetic material' was. "That seems more like a villain's quirk to me Deku. how can you save anyone with a quirk like that?" It was enough to make Izuku cry, and Katsuki made fun of that too.

He was playing in the park by himself to try and cheer up while his mother was off on a bench. Izuku was chasing a butterfly until he heard someone mumbling. Turning to the sound and following it, he came across a young blonde man with a scar running up his forehead sitting by the creek, talking about how 'am I me, no, I'm me, right?'. Izuku remembered the rule about stranger danger, but the man looked like he needed help.

"Um… are you okay?" he called from behind a tree. The blonde turned suddenly before he saw the green-haired child.

"H-hey k-kid. I'm al-no. I'm alright." he said brokenly. Izuku came from behind the tree and sat down, far enough away he could run if the man was dangerous.

"M-my name's Izuku. What's yours?" he asked politely. The blonde twitched and smiled, like he was in pain, but masking it.

"Bubaigawara Jin." he answered.

"You don't look alright, do you want me to get my mom for help?" Izuku asked quietly. Jin twitched.

"Yes! N-no! Can she? It doesn't matter." he answered, as if multiple people were talking from the same mouth. Izuku frowned at the confusing response. He decided to err on the side of caution.

"Don't go anywhere, I'll be right back!" the child promised before running off. Jin didn't move from his spot.

"Mom, mom! Someone by the creek doesn't look good, and he's not talking right. He may need help!" Izuku called to his mother, who reacted calmly and quickly.

"Alright, show me where. Was he hurt?" she asked while following her son into the brush.

"I don't know, but he kept talking about him being him, but not himself. It was confusing, but I don't know what to do to help him." Izuku responded. Soon Inko saw the man her son had talked about, and just hearing his mumbles, she could tell he wasn't in his right mind.

"Sir? My name's Midoriya Inko, my son asked me to see if you needed help." she spoke softly to Jin, not wanting the young man to panic.

"Help?" he almost whispered. "Yeah, I need-no I don't. Everything's fine-no, no, it's not." it hurt Inko to see anyone like this, let alone someone so young.

"Everyone needs help, Jin-san, or else they'd break. Let us be your hero." Izuku asked nicely, leaving Inko worried. Jin looked up from his mumbling and stared straight at Izuku.

"Heroes save the virtuous, not the broken like me." that… was the first thing he said without contradicting himself.

"Oh, honey." Inko cooed as she went up to hug him, her son following close behind. Jin flinched at the initial contact, but he thought, all of him thought, that it was better than being alone.

They were in the hospital, having Jin talk to a therapist. He had a duplicating quirk, and after cloning himself so many times, he couldn't tell if he was the real "him" or just the last clone standing from an all-out brawl. He left with a script, and a date to return on if to check if they were helping.

"Thank you both-I don't need-" he stopped himself before insulting them. "I'll try not to let your- it won't go to waste." though his speech broke, they knew the message was similar.

"It's more than alright dear. Do you have an address we can drive you to?" Inko asked. Jin shook his head.

"Couldn't- job didn't want- keep my job." he managed to get out. Inko took one look at him, sighed, and decided to go the extra mile.

"Would you like to stay with us then? At least until you get back on your feet." she offered.

"Huh?" was the blonde's intelligent response. "Why me? What did I do to be treated like I'm worth something?"

"You exist." Izuku said without hesitation. Jin looked at the child before smiling. He knelt down and hugged the first person who had just tried to help, and was changing his life.

"Thank you… thank you…" he kept repeating. The three left the hospital and Inko drove them home. In the passenger's seat, all the voices in Jin's head agreed on one thing.

These people are worth far more than me, so I'll help the best I can.

Izuku was turning twelve this week, and he couldn't be happier. His uncle Jin was living in a flat close by their house, visiting often. Eight years have passed since Izuku found the scarred blonde, and he now couldn't think of him anything other than as family. Jin had gotten better at his quirk, using it to make puppets (not copies, he's never giving them a will of their own again.) for Izuku to experiment his quirk with. When he got a result right, he'd change himself to get the new ability.

He did screw up though, but hopefully, that could be fixed. During a self-modification, someone interrupted his focus, and his body's chemistry shifted in the wrong place. His lower spine now hurt constantly from a malformed vertebrae, and until they could fix it, he wasn't supposed to tamper with himself.

The gene splicer was brought out of his musings by something crashing into him. Looking down, he saw a scared little girl, barely older than three. On instinct, Izuku picked her up and gave the little girl a warm hug.

"H-hey, are you okay?" he asked. She shook her head frantically and mumbled something Izuku could only just hear.

"I don't want to go back there…" her voice was weak, and Izuku noticed her lack of weight. He took a glance down and saw her arms under her unkempt hair covered in bandages.

"Alright then, how about we go to my place, and we can call the police and sort this out. You don't have to go back." Izuku's voice was as soothing as he could make it, but seeing her grab him like he was a lifeline, tears fell from the genetic writer. He ran back home, forgetting all about school. He slowed down gradually until he briskly walked up to his front door and threw it open.

"Mom, call the police!" he yelled as soon as he closed the door. Inko came running down the stairs, ready to ask what happened, when she saw the tiny girl shivering in his arms, holding on like she was scared for her life.

"Alright then. I'll also call the school and tell them you're not coming today. Get her some food." Inko said with a fire in her eyes; no little girl should be that terrified. Izuku nodded and walked into the kitchen.

"Alright then, what do you want to eat?" he asked, but the little girl didn't respond. Taking a safe bet, he picked an apple and a small knife, careful she didn't see the sharp tool and panic. He cut the fruit up into little rabbits as his mom showed him, though they weren't as pretty as she made them. Putting the knife out of sight, he pulled the ash-haired girl from his chest. He was a lot taller than her, due to both his self-modifications and her tiny frame. She was reluctant to let go, so Izuku sat on the chair while putting her in his lap.

"I made you some apple bunnies to eat. Would you like some?" he gently prodded. The little girl nodded before taking one slowly. As she ate the first apple slice, her eyes widened and she quickly reached for another and ate it quicker. Izuku smiled as he took his time looking over his charge. Her eyes were red, and her hair was just shy of white, so he guessed she was albino. The odd thing was the yellow horn sticking up from the right corner of her forehead. She was skin and bone, and far too light for someone her age, meaning she was probably underfed.

"Un…" the pre-teen was brought out of his musing when she finished her plate.

"Would you like some more?" he asked politely. she nodded and he picked her up again. Questions could wait; right now, she needed a hero, and Izuku would be damned if he wasn't going to be one for her.

Holy cow that was a lot of scenes I wrote. Anyway, a thought came into my head while watching someone go through Bioshock 2; what if ADAM was in the My Hero world? Then the idea of a Big Daddy Izuku caring for Eri, and I decided to say 'what the hell?' and write it. So yes, Izuku is technically a Little Sister (brother?), and will grow up to be a Big Sister (brother). Also, looking at how Kohei wrote Eri's quirk, I thought she'd be a good counter to Izuku, and vice versa; one can evolve, the other can reverse evolution. Jin I'm writing as in his early twenties, because the cloning problem he had sounds like a college fuck up to me. Eri is three, because story reasons, and the translation I read of MHA said quirks usually showed up around age four, not at, so hers came in earlier. Anyway, there will be a few more Bioshock references, but not enough to count as a crossover. Thank you for reading, leave a comment, and till next time!