Izuku has gotten used to being underestimated for the majority of his life. It's been because of many things throughout the years: Quirklessness, small physique, shy outward nature ect. Stupid things he can't really control, but he's learnt to live with it.
He uses it to his advantage now.
In middle school he'd been bullied, yes, but he'd come to understand that if he played the part of small, weak, cry baby Deku people left him alone. Sure Bakugou was lecherous in his attempts to put Izuku down but despite that it worked.
People saw what they wanted from him, and because he played the part he was left alone. It wasn't fool proof and sometimes other people besides Bakugou would try their luck.
But even then, because they underestimated him and only saw a weak child who could never be at their level, they went easy. And in the slips in their guards because 'What's Deku gonna do? Snitch?' He learnt everything he needed to avoid them, to beat them, to break them.
As he'd grown older, wiser and jaded to an extent, he'd gotten better at slipping behind the facade of a shy, quirkless boy who dreamed too big and wouldn't hurt a fly.
He never had friends but despite his quirklesness he had been generally well liked by his classmates. And the facade that he had developed to buffer the attention from his real calculating and frustrated nature had only ever been questioned once.
"Don't you worry that one day he'll snap? Just because he doesn't have a quirk doesn't mean he couldn't kill someone!"
Izuku had pretended to be engrossed in rereading his hero notes, his last two books had started to have segments of villains and criminals including things that made them hard to catch and things that made them good at escaping.
There had been a laugh from the general direction the question had come from. "Deku? Seriously? The guy could get knocked over by a strong breeze, he isn't dangerous . "
The query was forgotten and life had continued as normal but it had gotten Izuku thinking.
So far his facade had been a bullying deterrent. A way to keep the dogs off his scent so to speak, so that he could follow his dream to the best of his abilities without Bakugou and his cronies yapping at his heels the entire time.
After being told that he didn't appear dangerous he'd understood that that was something he could use. After all, the minimal footage and exposure Erasure Head had proved that he was an unassuming figure and didn't look strong or dangerous.
Erasure Head used that and took his enemies down quick and hard, with nothing more than speculation as to HOW.
With that knowledge he'd asked his mother for martial arts training, they'd whittled away, arguing and presenting reasons as to why and why not. Eventually they'd settled on self defence and it was there that he learnt his most important lesson, Never underestimate your opponent, let them underestimate you.
It had continued from there, self defence turned to Tae Kwon Do and that turned into nothing else as he disciplined himself and tried as hard as he could to progress, but nobody learnt belts over night. In the dojo it seemed that the only place he would not be underestimated was in the ring.
For that he was grateful.
As two years passed, as he became less jaded and more open to his fellow trainees (he still never had friends. Quirklessness was still a barrier many refused to breach) his classmates began to solidify this image of him in their heads.
Bakugou insisted that he was a lying, cheating bastard who was looking down on them because did they not see that he was getting stronger, that he was becoming more confident behind his cheap little mask that he put up?
Thankfully, nobody believed Bakugou and over time the accusations dimmed, becoming less angry and more resigned. More targeted that no matter how strong he thought he was he would never be as strong as Bakugou.
From that Bakugou also underestimated him.
It carried over to U.A. as well. He'd been surprised at that.
Hadn't they seen him at the USJ- heart in mouth broken finger and murder in his eyes- throwing himself at the Nomu, at Kurogiri with the intent to harm?
Hadn't they seen him in the sports festival - Eyes wide and manic, power shattering his body as he broke through layers and layers with a sledgehammer of spite and sheer force of will?
And hadn't they heard him in the stands, when Uraraka asked him what he was writing about and he revealed that he had files on ALL of them?
Hadn't they seen, heard about damn it hadn't they read about the involvement he had with the Stain case? How he had supposedly helped Endeavour into taking down the hero killer?
They had, and yet the idea remained that Midoriya Izuku was not dangerous.
He was kind, caring, a cry baby at times but a determined kid at the end of the day. Nobody dangerous.
Reading between the lines he realised something. For years people hadn't not found him dangerous, they'd always assumed he wasn't dangerous to them. It was a game changer then, realising that people didn't see him as a threat because he never seemed like one.
Bakugou was never perceived as a threat, because whole considered violent and 'dangerous' he wasn't dangerous towards the class. He blew up and swore yes, but he didn't intentionally hurt people. He didn't sit awake at night planning how to take his classmates down in every situation his mind could conjure up.
Or, at least, he didn't think Bakugou did. Maybe he did and he and his childhood friend were disturbingly similar in that regard as well, the first point of disturbing similarity being their unwavering love and devotion to All Might.
And then there was his mentor. Even All Might, symbol of peace, man of many smiles and seasoned hero of nearly forty years didn't see him as dangerous. He was more open with his mentor, the facade sliding away to hopefully prove that he could be dangerous if he wanted to.
It didn't happen. Instead he was constantly told how much of a 'hero of the people' he was. How 'unthreatening' he was and how admirable that was in a future hero candidate.
That had always bitten at him.
He didn't want to be dangerous, or seen as a threat. But he... He wanted to be seen. To not be 'shy, awkwardly friendly' Deku or 'slightly intense, scholarly' Deku and he most certainly wanted to stop being seen as 'Goody goody' Deku.
In thinking it over he realised that he wanted to stop being Deku, and start being Midoriya Izuku again.
Midoriya Izuku swore, Midoriya Izuku had near obsessive notes on heroes, villains and classmates so that when push came to shove he could fight.
Midoriya Izuku sat up late at night running contingency plans through his head. His friends, family and teachers the subject of many ludicrous plans that would never happen and his mind bending and flipping a hundred different ways to fix them problems.
Deku didn't do any of that. He was quiet, mumbled a lot and got nervous around new people before morphing into a slightly less quiet and less nervous kid who rambled on about heroes.
It was like two sides of a coin. Heads and tails, mirrored yet reversed.
The only time he could be Midoriya Izuku was around people from other classes, like Shinsou and Mei. He'd spent a few lunch times hiding away in Mei's lab, chatting and helping her tinker with and think away at new 'babies' while Shinsou lounged on the beaten and dead sofa Mei had pushed up against the wall in her supposedly shared workshop, occasionally interrupting debates with input of his own and the more occasional summons to look at cute cat pictures.
(There was never another inventor in the lab and the door read only his friends name. So Izuku was starting to think the lab partners had either requested a move and Mei never noticed or the pink haired gremlin had pulled a Neon Evangelion.)
Midoriya Izuku thrived in the workshop, where he could discuss the lethality of his plans without provocative and without judgment- the other two joining in saying when it went to far or when he could push it just that little bit more.
He thrived where he could lie down and tension could leave his shoulders and he could swear and scowl and not be happy and smiley. And he could be tired and stressed.
There was another occasion he could be himself as well, though this one was constantly overlapping with the first.
Monoma Neito was a frequent visitor at the Hatsume forge (it was supposed to sound intimidating apparently but it made Izuku think of a soft jrpg npc location) constantly asking about support items and licenses and, when the Sun and moon were in the right positioning he seemed to also enjoy having a normal conversation.
They'd begrudgingly gotten used to each other, and at times Monoma joined in with debates between himself and Mei, sometimes the blond would just speak with Izuku out of sheer wanting to about various topics.
The sports festival, despite causing him to injure his arms beyond repair, had gifted him with friends and an unlikely... acquaintance though he suspected Monoma would drop dead before admitting it.
He was thankful.
Uraraka, Iida, Todoroki and Tsuyu were all wonderful people but Izuku had to admit that the company of Mei, Shinsou and Monoma was more welcome at times than the near suffocating friendship with the others. Since being given the opportunity to be...free he'd felt confined.
The constant use of Deku and Midoriya rather than Izuku, Mido and idiot (Monoma often sounded calm when he called him that, no venom visible or heard) hit home how tightly he kept his more open personality close to him.
He, again, felt so so thankful that he'd had the opportunity to be close to them. He was especially thankful when exams started up and Monoma agreed to help him study, claiming that '1-A's poster child needs to be at the top of his game.'
He'd never been given an explanation on the poster child comment, but the blond's tutelage had helped exponentially and he'd exited most of his exams with a breath of relief rather than of despair.
The post-test haze that had settled over the class had been pushed aside as some classmates made up for lost time getting back into hobbies while others trained and trained hoping for the opportunity to release their quirks to their hearts desires.
Then you had others, like Hagakure, Ashido and Kaminari who had gone information hunting. They'd come back with news of practical exams. Of tales from 1-B's class rep (Kendo was nice, she was another he could relax around) about past years experiences.
Entrance exam reruns, days after days of spontaneous hero practicals, and the more intense ones being week long lock ups in training grounds.
He'd been enticed by the idea of that last option, and soon discovered that it was a simulation test. The hero classes would alternate between who had the leaders in it (it changed each year this particular exam ran apparently) and then the two leaders would be named either villain or hero and they were given a week to prepare before being locked in a training ground for a week.
The objective was to test both sides on different parameters.
The villains prompts were often to create havoc, to create as real a simulation as possible. -The footnotes on the documents he read through detailed about how they were judged on acting as well as actions.- Along side that they had certain parameters to meet. Things to steal, 'people' to kill and places to destroy.
With the added bonus prompt of 'killing' off as many heroes as possible.
Clearly the leader and their team were assumed to be those who would consider going into underground or undercover positions so playing the villain would be practice he guessed.
Reading through some of the past schemes he realised it was also an opportunity for people to learn to think outside the box, to make a situation fit for them, instead of waiting for it to.
The heroes prompt was much simpler. Win.
Take the villains in, don't 'kill' them unless absolutely necessary (there was no indication of fake weaponry in the guidelines so he suspected it was the prerogative of the students to find a way around this.), stop the villains plans and get them to surrender before the week long exam finished.
Reading through the few reports (the activity received controversy each time it was activated so it happened once for each year very decade) he saw that the longest the seven day time limit had lasted was three days. And the three times it had been run heroes had never lost.
Spurred on by interest he soon found himself diving into rule books, theories and data analysis from past students on the exam. It was such an interesting concept. More invigorating, more spontaneous and more fitting of up and coming heroes in their world today.
The concept of the activity was to teach the villains to work under intense pressure and against stacked odds and learning to trust your gut and ignore moral guidance for the greater good at times.
And the concept was also to teach both sides how to deal with city warfare and sieges. Something that as of late was becoming a bigger and bigger threat.
It had been massive in the early years of heroism. As villains and heroes alike acted more like soldiers rather than peacocks with nuclear explosives strapped to their chests.
Now, his generation were coming into a world of heroism where a battle between a hero and a villain was not too different than a war anymore.
He didn't get his hopes up and went back to training for the two most obvious choices for their exams. A redo of the entrance exam and a week long spontaneous heroics class.
He was shocked, when two days before the announcement for what their practical exam was going to be they were told they would be living in dorms.
The only explanation given was that the school had been meaning to for years and decided now that with all the encounters the first years had had they were finally sold. Not to mention, Present Mic had told them, training camp was coming up after the exams finished. Wasn't it better to get used to sleeping under the same roof sooner rather than later.
Izuku was fine with it as long as he didn't room with Mineta.