Disclaimer: I don't really see anyone do this in the BNHA fandom but, since I'm accustomed to doing in when writing my Pokémon fic. I don't own the BNHA franchise as that belongs to Kohei Horikoshi
Alright, other than that, this fanfic just came to my head when I read a story by the name of Angel on my Shoulder by TealeafCustom (a really well-written story that I think you'll all enjoy to some extent.) The quirk that he gave Izuku was fascinating but it gave me inspiration for the quirk that I'll be giving Izuku in this story, a quirk that I haven't seen anywhere else on the website. So, without further ado, let's begin.
Izuku Midoriya yawned as he sat at his desk after school. He always took a little longer than the others to put his things away, usually adding some things to his Hero Analysis notebook. Not much had happened during the day, other than the fact that the teacher had told the class that both he was attempting to join UA, which gave him a few laughs and jeers.
He gave little to no care that they laughed at him for trying to go to UA, forgetting about it entirely when started writing in his notebook. It was during the time when he was detailing Mt Lady's strengths and weakness, when his fellow classmate, Katsuki Bakugo had walked into the classroom and snatched his notebook off of his desk.
Izuku gave Katsuki a confused look, he tried to avoid the blonde as much as possible, "Kacchan, give it back. I don't want to use my quirk, alright. You remember what happened when we were four. You've always hated me because of that."
Bakugo flinched a little. He quickly recovered and made an indifferent look, holding the book with both hands. He started sweating a little so that he could use the nitroglycerin-like sweat to blow the book was with little to no sadness that Midoriya looked at the book and saw it blown up with smoke emanating from the notebook. Bakugo threw the book outside one of the windows without a second look, to which Midoriya only replied to with a small click of his fingers. This seemed to be unnoticed by Bakugo.
The blonde turned back to Izuku with a smirk on his face, "Seems your quirk isn't very useful, Deku. Maybe you should try to take a swan dive through the window, you might get a better quirk in your next life."
Bakugo looked at him with a final grin, knowing that he had won. With that done, Katsuki started walking towards the door. Just as he was about to leave, he heard the window open. Crap... The blonde looked at the desk that Izuku had sat at and noticed the boy's absence. He rushed over towards the window, subconsciously hoping that the boy hadn't gotten killed because of him: that would ruin his chance at getting into U.A completely. He looked down expecting to see a red splatter of blood on the ground. Instead, he saw Izuku sitting on a crystalline-white tile around four metres below, holding the intact notebook in his hand and reviewing his note.
"What, Kacchan? What did you think I would take your advice and throw myself off of a window? I just wanted a nice view," Izuku said with a grin, showing his notes in front of him, "I just needed a little ledge to sit on so I used my quirk. Not so useless is it?"
Izuku smiled, lying down onto the tile with a smile whilst looking at Katsuki's confused face. His quirk allowed him to make the tile a little longer so that he could stretch his legs.
The quirk wasn't a flashy one. Instead of being able to cause explosions, or to release fire or one of the enhancer quirks that many heroes had, he could summon a self-producing white, crystalline material and do a whole ton of things with it. There were multiple pros and cons for using the material but the main two things that needed to be remembered was that the material was very fragile and extremely lethal.
The material couldn't take many hits, if any at all, only one of Bakugo's explosions would be needed to destroy a solid three-meter thick wall. In fact, the only reason that it could Midoriya's weight was due to how he had created it (making it an extension of both himself and the building when he was falling.) The thing with Izuku's quirk was that it was able to completely replace the very atoms of any other material or cell, giving it a superhuman precision.
He could also remove it, restoring whatever atom he had just replaced. Izuku liked to compare the quirk to a sticker: when you apply the sticker onto a picture, the sticker replaces the area of the picture it is covering. However, like a sticker, you could also remove the sticker to leave the image intact, seemingly as if nothing has ever happened. Like a sticker, he could use the adhesive to rip a bit of the picture off. The objects would be stored in the pocket space that the material came from and would only stay in there for about an hour before it was completely converted into the crystalline material.
Outside of the sticker analogy, he could enable and disable the effects of gravity and any other force that tried to push against it, meaning that, instead of moving, the material would take the brunt of the force so whilst things like gravity wouldn't break it, a single punch would shatter everything.
The other thing that he could do with the quirk was shattering both it and the material it was replacing, destroying them totally and irreversibly. This was what made his quirk so indescribably deadly and destructive, with it he could completely remove a person's internal organs with little to no effort or fill their lungs with a click of his fingers. There were seemingly zero drawbacks to this other than the fact that, if he isn't careful, he could completely destroy parts that he didn't mean to.
Of course, since it was precise to the atom, his summoning quirk came with the ability to feel each atom, altering each and every nanometer as he needed. It wasn't like sight though, more like a probe or when you brush your hand over a bed of grass and feel each blade touch your finger. Time seemed to slow whenever he started using the probe, giving the disorientating effect of seeing through his eyes at an alarmingly slow rate. In fact, it was almost like time would freeze for what felt like an enormously long time before he noticed a slight change. Thankfully, he didn't need to use the slow time feature when he activated his quirk, though it made things way less precise.
The only thing that stopped it from being completely overpowered was that it was finite so he had to be careful with it. However, he'd get an average of around 5m³ of the material every time he went to sleep so he could easily restock.
A few minutes later, Izuku slipped the notebook back into his bag, seeing Bakugo on the pavement, before using the quirk to make stairs so that he could climb back into the window and go home. If Izuku were honest, he was always a little jealous of his classmates' quirks but he knew that the one he had was perfect for him. Great for people who can analyze and find weaknesses in the heat of battle as well as one that could be utilised for casts and light medical applications.
Once he'd gotten onto the bottom floor, he laughed to himself as he walked home. Another day down, another day closer to joining the school he'd always dreamed of, UA Hero Academy. He'd spent near enough every day fantasising about the one day where he can say that he was a student to one of the greatest hero schools in the world, the school that All Might himself had gone to.
Yes, he wouldn't let anyone put his dreams down, he's proven that when he first used his quirk, against Kacchan of all people. He had grown up since then, preparing for his goal, to become the greatest hero the world had ever seen, surpassing the heroes of today and fighting against the villains of tomorrow. It was with that thought that Izuku heard a manhole rattle, he gave it a quick look before he felt something slithering against his leg. Not a big deal, Izuku thought, using his quirk to reach just a millimetre above his skin and preparing to put it inside his pocket space when he noticed something odd with his probe.
The slime wasn't made of atoms, it was full of cells. Not just bacteria that he often had to deal with, there were brain cells, blood cells and other things that were normally found inside the human body. He glanced down at his leg only to realise that there was a green goo moving from the manhole and onto his body.
"Don't scream, kid," the student heard a voice whisper as a slight weight moved just behind his ears, "I'll only be taking control of your body and framing you for crimes. Don't worry too much, you won't be alive to see the consequences..."
Correction: the slime wasn't moving onto him, it was moving into him. As Izuku felt a drip of slime enter his mouth, tasting of putty and mucus, he activated his quirk, filling his mouth as well as his nose and ears with the ivory-coloured material, before pushing it out of his mouth and covering his entire body within an inch of the material.
"You seem to be rather stubborn," he heard through the sheet, "Don't worry, there has to be an opening."
There wasn't. Unless the slime fit through gaps the size of atoms, there were absolutely zero openings. Izuku knew that he couldn't stay in his sheet forever and, after some brief thinking, he knew that he needed to trap the villain though he needed to also create a way to escape. Once the green-haired boy felt that the weight pressing against his armour-of-sorts, he formed a second wall around fifty centimetres away from the first, pulling it closer to his body until he noticed that he was pressing just against the goop.
With it completely surrounded, Izuku created a centimetre thick wall in front and behind him to separate the slime villain into two boxes on his left and right. With that done, he moved the containers away from him, allowing him to move a good few steps before he reconnected them together and shattered the centimetre thick divider. Now with a box full of monster slime, Izuku hovered the box beside him, mapping out a quick detour to a local police station so that he could put the villain behind bars (figuratively since the villain would probably be put inside a glass container for the rest of his days.)
He was only able to make a few steps before another manhole rattled. Prepared this time, he blocked the manhole with his quirk, stopping another slime villain from attacking. He didn't expect the material to shatter into nothingness and for a human arm to reach out.
Keeping his guard up, Izuku was ready to remove the intruder's eyes (and likely a large chunk of their forehead) before he realised who it was. To his surprise though, All Might jumped out of it despite his huge size, not expecting to see a young middle-schooler instead of a puddle of slime. Once he noticed it was All Might, he brought his hand down and sighed before quickly realising that he had stopped All Might from capturing a villain. He didn't want the number one hero to think of him as a nuisance after all.
All Might gave a hearty laugh once he'd heard Izuku apologise, telling him to calm down and explain what had happened. It quickly became apparent to Izuku that All Might had been going after the villain that Izuku had captured.
"Ah, so you captured him. Well done, my boy. I expect to see you at a hero agency within a few years. Now, would you like an autograph before I go?" All Might said with an earnest and proud expression, "After that, I will take my leave with this box. It breaks as easily as the cover over the manhole, am I right?"
Izuku nodded as he gave All Might his notebook to sign, elated by the fact that All Might, the All Might that had inspired him and continued to inspire him to be a hero, had praised him. He was ready to spout something about making it an heirloom before realising that he had a single question for All Might.
"Hey, um, All Might. I have a question for you about the usage of my Quirk? Since heroes should tackle most situations non-lethally, would it be ethical to create temporary or permanent disabilities?" Midoriya asked, needing some kind of guideline for his quirk. After all, with an overpowered ability, it must be scaled down for appropriate, practical use.
All Might gave him a confused look, from what he'd seen, the boy could only create a white material, "What do you mean, Young..."
"Oh, erm, I'm Izuku Midoriya and my quirk lets me summon a material that will replace the very atoms of the universe. With this quirk, I can block out someone's eyes, shut off nerves in the fingers or simply block veins and arteries so I need to know the best way to use my quirk. I want to know if my quirk would be a liability if I were to become a hero," Izuku said, hoping that the Pro would give him some advice.
"Well, if the disability is temporary, I believe it will be accepted by the public. Though, I will say that blocking veins may be heavily reprimanded by the public. In other words, I recommend blocking sight and smell instead of blood supply..." All Might said, a smile on his face, "Well then, I hope you feel that you've gained something from this little talk. You've got a powerful, versatile quirk and the intelligent, creative mind to make it effective against other people, Young Midoriya! I hope you plan to join a hero course, maybe give U.A's hero course a try! Now, heroes must continue to work and protect the people. Farewell, Young Midoriya!"
Izuku smiled as he watched All Might shrink as he jumped higher and higher into the sky. He ran the events through his mind again, and then a few times after, giddy with the fact that he had aided All Might in the capture of a villain.
After fifteen minutes, Izuku made it home and greeted his mother with a smile, ready to tell her all about the fact that he had helped All Might in arresting a villain. Needless to say, Inko's chest swelled with pride as she heard how All Might had praised her son. She needed to make some sort of special meal to reward him, and her mind was running through quite a few. After that, Izuku went to his room and looked at one of his shelves. Like most people, Izuku was a huge fan of All Might and most of his room showed it. There was one other thing that was extremely common in his room: sculptures.
With his quirk, Izuku often made sculptures with his quirk. They were mostly less than five centimetres tall and always less than two centimetres thick except for one. Whilst most of the sculptures were simply 3D models of his family and heroes that he admired, there was also a larger sculpture which really tested Izuku's quirk. That was the large model of Izuku himself: a model that was exactly to scale. The model showed Izuk smiling with his hands to his sides and an ever-changing array of clothes. Izuku would usually spend half an hour in the morning as well as a full hour at night to change the model to a precise version of his body, filled with his muscle groups, veins and arteries as well as his entire skeletal system. The only area that Izuku had some trouble with was the brain. He was able to make an accurate copy of it with all of the nerves in place but he couldn't understand it all as easily as he could understand the muscle system.
Ever since he had started this project of self-creation, he had become much greater at human biology and understanding how human anatomy worked. Hell, he could probably attempt to get a diploma in cardiology simply because of how much he struggled understanding how his heart could beat in its confined space. And, as a side benefit of creating a copy of himself every day, he was always able to remove foreign bacteria and viruses which made him near immune to all viral infections.
There were also quite a few stories relating to the statues. For example, when replicating Inko, Izuku had completely thrown off his mother's menstrual cycle when he mistook the egg cells for some sort of deadly infection. Needless to say, Izuku's mother had been panicking for quite a while before Izuku told her, unaware of what he'd just done. But, whilst that was one of the greater stories to do with his quirk, none would ever match the time when the quirk first awakened. It had been he'd finally proved to everyone that he wasn't useless or weak and it was also the day he had finally put Kacchan in his place.
It had been about ten years ago and Izuku, as well as Kacchan and his friends, were at the park, enjoying themselves when things turned for the worse. A boy around their age had stumbled into the play area and simply sat down and observed them, something which gained Katsuki's attention.
For a reason that Izuku didn't understand, Bakugo became enraged by the boy's presence and decided to overpower them with his explosive quirk. Usually, Izuku would try to calm the blonde down verbally but, in that one instance, he decided that he would shield the boy with his own body. After all, it wasn't like Kacchan would ever hurt him, right? Well, he was wrong, Kacchan shoved his palm right in front of Izuku's face and detonated, causing a sizable blast to strike Izuku at point-blank. And that was when Izuku's quirk kicked in, Bakugo was meant to cause multiple explosions but he stopped abruptly after the first one.
Instead of skin and flesh, both of Katsuki's forearms were replaced with the smooth, crystalline material which meant that there were no sweat glands to produce the sweat needed for his quirk. It took a few moments before anyone realised what had happened. Izuku, Deku of all people, had removed Bakugo's quirk and beaten him that easily. The boy behind Izuku quickly ran away, seizing the opportunity to escape, but not before telling Izuku that his quirk was awesome. That single compliment really meant a lot to Izuku, telling him that he had been an actual hero in the boy's eyes.
After a solid minute of disbelief, everyone rushed home to avoid anymore fighting. Izuku was able to tell his mum about the whole experience and how he had saved someone like All Might did. On the other hand, Katsuki had to suffer through three days of not being able to move or feel his arms before Izuku finally decided to remove the material and return Katsuki's arms to the blonde (Izuku learning how to remove the material in the first day but waiting until the third before he actually removed it.)
Midoriya liked to think that was a nice origin story. It was no cinematic masterpiece or pinnacle of storytelling but it was still a story of saving someone and becoming a good person, even if it could be argued that waiting until the third day was a rather cruel, dick move. Welp, you win some, you lose some. And Izuku's quirk was well worth the somewhat ethically ambiguous origin story. He enjoyed that memory far more than most would, simply due to how exhilarating it was to overpower. He decided that, with nothing else to do, he could create another sculpture, maybe even one of the slime villain that he had aided All Might arrest.
He chose not to probe the atoms like he normally would, instead deciding that he would create it in real time. Due to the simplistic shape of the villain, the small-scale replica of the villain needed way less time than the daily upgrade to his own body's replica.
45 minutes later, his mother came into the room, like she usually does to check up on him and see his sculptures. However, she seemed panicked once she saw the sculpture that he'd made... almost as if she recognised it from something she'd seen.
"Izuku, what are you making?" Inko said, holding in a breath.
"It's that villain I told you about earlier, the slime one that I contained in a cube," Izuku said back, an eyebrow raised, "Why do you ask?"
She scratched the back of her head, "It seems the box broke earlier. Just, look at the TV and see you'll see a few familiar faces."
Izuku was really confused now, flicking a finger and moving the replica's atoms towards an empty shelf with his quirk, giving off the impression of telekinesis. With the replica ready to be finished later, Izuku walked into the living room only to see two very familiar faces.
Of course, it was the two people that had confronted him at some point today. Every good thing comes in threes... Or was it every bad thing? Both fit the situation and given that Izuku had been the only person in both confrontations, he'd be needed for the third.
Putting his shoes on, Izuku told his mother that he would be going outside to check it out. After all, he was the one who had beaten the Slime Villain once and thus he should be able to do it again. Using his quirk to run over the buildings between him and Katsuki, he made it there within five minutes, spotting some Pro Heroes observing the scene. It was a hostage situation and they didn't want to risk the chances that the hostage might be killed.
Izuku made a final run-up towards the edge of the building and leapt off of it, using his quirk to break his fall every few metres. No one seemed to notice his entrance, everyone staying fixated on the Slime Villain. With his presence unknown, Izuku probed the cells, looking for the rods and cones found in the eye. With them located, Midoriya snapped his fingers, causing the Slime Villain's eyes to turn pure white.
Midoriya heard the scream of fear and used the confusion to his advantage. Creating a centimetre-thick layer of crystalline material over Bakugo's body, he lifted the boy out with little resistance. With Katsuki out of the way, Midoriya clicked his fingers again to summon a large box around the villain. Last time, the box was easily broken so he needed another way to transport the villain. Shrinking the box so that the lining was always in contact with the slime, he brainstormed some ideas.
"Does anyone have any empty water bottles or containers?" Midoriya asked, thinking of an easy way to transport the villain, "Well, if you don't mind me putting the villain in it..."
A woman to the left of him, a driver for a shipping company, carried a few empty plastic boxes and handed them over so that he could lock the villain into them. Creating a little slit in the crystalline box, he shrunk the box even further, causing the slime to drip out.
With two boxes filled with a slime villain, Izuku sauntered towards the pros and dropped the box at their feet. He gave them a wave before starting to walk away.
"Hey, young man!" he heard a gruff voice say behind him. The voice belonged to Death Arms, a Pro hero who'd been at the scene before Midoriya, "What quirk did you use back there?"
Izuku scratched the back of his head and decided to explain it in the simplest and most laconic way he could think of, "I have the ability to summon a white material which will temporarily replace the atoms it is summoned on and manipulate it to my liking. I blinded the Sludge Villain by replacing their eyes before locking them into a box and removing the material."
Death Arms seemed to follow, "Whilst I will say that you aren't meant to use your quirk in public, I must commend your heroism. You saved that boy's life and I'm sure he's thankful for that."
Izuku sweatdropped, knowing that Katsuki wouldn't appreciate the gesture as much as Midoriya would like. In fact, he should talk to Bakugo quickly, to make sure he knew who saved him.
"Hey, Kacchan!" Izuku called out with a smile, "I see you've been doing good today!"
Midoriya gave him a final smirk before running towards an alleyway so that he could sprint back home above the buildings. Quickly creating a ladder to climb up to the roof, Izuku sprinted back home as fast as he could. He had to tell his mother how awesome he was feeling right now. He was able to cover four blocks, enjoying the slow meandering breeze pass him before he felt much faster air whoosh past him. He looked to his left and saw All Might, a large grin on the Pro's face.
"It appears I wasn't wrong in my assessment of you, Young Midoriya!" the blonde said, "I saw you're quick to action when you were saving Young Bakugo! Would you please slow down for a second, I have something to say to you?"
Izuku stopped in his tracks, thankful that he was on a solid building instead of being above a street or road. If he had been so unfortunate, he may have had to deal with a long drop. He turned to All Might with a confused look, had he done something wrong? It was probably because he was using his quirk, right?
All Might gave him a pat on the back before telling him, "You see, as a hero, I've been becoming weaker and weaker. Do you know how long I'm able to work nowadays? The answer is too short to continue being the symbol of peace. And if I am too weak, then I must look for a successor who can continue to carry the mantle!"
Izuku gasped, had he understood this correctly, "Y-You believe that I might be able to become the Symbol of Peace. I'll try my hardest to live up to your expectations!"
All Might smiled at him, "Well, that has something to do with it. Whilst I believe you may have what it takes to become the Symbol of Peace, I have another offer for you."
Midoriya rose an eyebrow, what kind of offer would help him become the Symbol of Peace, "Y-You mean you'll train me to become a Pro Hero!"
All Might's smile became even larger, "Well, that's also part of it. For, you see, I'm not offering just you the knowledge to become the next Symbol of Peace, I'm also offering you the power... I would like you to take my quirk!"
Midoriya looked confused but not dumbfounded, "And how would you give someone your quirk. It just isn't possible with modern technology."
"You must look away from technology and turn to biology. You can't remove a quirk from someone's body and then give it to someone else unless that was part of the quirk itself!"
This really caught Midoriya's attention, "Well, that would that either you were born with a quirk mutation or... You weren't the first one with the quirk"
"Bingo, Young Midoriya!" All Might gave him the largest grin he could, "The quirk you know me for has been passed from one person to the next. It's called 'One for All' and it has been passed down in order to stop a great evil and protect the people. And, I hope it will become your quirk soon if you so choose."
Izuku's eyes sparkled, "Y-Yes, of course! If you that much faith in me, I must be able to do it!"
"Well then, Young Midoriya! Prepare yourself both in body and in mind. After all, the next Number One Hero must train hard enough to beat all evil. So, join me, Young Midoriya! Begin your path to heroism."
"Y-Yes! Yes, of course!" Izuku said with a huge smile, "Of course!"
And, that's all. I had this idea for quite a while and just needed to get it down. If you enjoyed this, please follow or favourite the story. If you've found any grammar, spelling or continuity errors, post in the comments and I will fix it. Have a good, day!