Author's note: Hey everyone, Fire Slash here welcoming you to the second of my four planned Marvel/MHA crossover fics, Iron Deku. Before we get started, I'd like to address some things. First, as there's no way a kid as young as Izuku would get kidnapped by terrorists to build a weapon like Tony Stark did, I had to come up with another reason for why he'd build the suits of armor. Secondly, the main pairing in this fic will be Mei x Izuku. In a story like this, not pairing them would be a sin. Third, you'll notice this Izuku will be more confident compared to his cannon self (except in social situations). This is a result of his newfound intellect. He'll still be the same as cannon otherwise. Finally, those of you who are waiting for another chapter of my other MHA/Marvel fic Silent Deku, I should have that out in a few days.

Well, I've finished what I've had to say, so let's get to the story already. Review and enjoy :-)

0000

No one was born equal, such was a universal truth. Some people were simply more gifted than others. This was a fact Izuku Midoriya learned when he was diagnosed as quirkless at the young age of four. In a society where quirks, the name given to the sudden superpowers eighty percent of the world developed, determined your worth, being quirkless made you a nobody. After all, how can someone without a quirk compete with the powerful majority?

"M-mom? I can still be a hero right? I c-can still be like All Might, right?" Young Izuku Midoriya asked his mother the day after he was diagnosed, tears streaming from his eyes. All the boy wanted was to become a hero like All Might, the current number one hero, but without a quirk, his dream seemed to be out of his reach. All Inko Midoriya wanted to do was reassure her son that he could still be one, but she knew that she'd only be giving him false hope. Instead, she wrapped her arms around her baby and continuously apologized for the cruel hand he was dealt. What she didn't know was that by not believing in him, she was hurting him far more than the diagnosis did…

0000

A week later, Izuku was back on his feet, the lack of a quirk seemingly having not bothered him. Of course it still stung, but he wasn't going to give up on his dream. No matter what anyone said, he couldn't stop just because of a stupid birth defect. All Might would never give up, so why should he? Being quirkless simply meant he'd need to work twice as hard, and that's what he ended up doing…

"Mom! Mom! Can we watch this one?" Izuku asked his mother. The two had a tradition in which they'd watch a movie every Sunday.

"Hm?" Looking up from the dishes she had been washing, Inko noticed her little bundle of joy holding a copy of an obscure American movie about a man fighting crime in a suit of armor. Glancing at the box, she let loose a sigh of relief upon finding out it was child friendly. Izuku loved superhero movies, but he was only four and most of those movies are made for a teenage and young adult audience. As such, it was tough finding one she was comfortable with him watching. "I don't see why not. Just give mommy a few minutes to finish the dishes, ok?"

Nodding, Izuku ran to the living room sofa and plopped himself down, waiting impatiently for his mom to finish her boring chores. Eventually she did and began playing the movie.

"Hey mom, how come he hasn't used his quirk yet?" Izuku asked halfway though the movie, still not having realized the main character was quirkless.

"He's quirkless sweety," his mother responded.

"Quirkless? I thought you said quirkless people couldn't be heroes…"

Wincing at his choice of words, Inko began explaining the bits and pieces of the movie to him that she knew he didn't understand. "See the armor he's wearing? He uses that to fight people with quirks. He relies on his smarts, not strength to fight."

"Really?!" Izuku asked, his eyes sparkling at the idea that someone could become a hero without a quirk. Wait, if he could get himself one of those armor thingies, then could he become a hero?

"Of course, this is only a movie. I'm not sure how someone like him would last being a hero," his mother continued rambling, but Izuku had blocked her out at this point. All that was on his mind now was how he was going to get himself a suit of his own…

0000

For the next five years, Izuku spent most of his time developing his skills in the engineering department. Having learnt that the main protagonist of the movie made the suit himself, Izuku was desperate to make himself one as well. At first, Inko thought nothing about it, after all, how on Earth was a four year old going to build such a machine? These five year ended up being a wake up call for her, causing the woman to learn several things about her son she didn't know before. First off, the boy was incredibly intelligent to the point he could be considered a prodigy. He was able to grasp the basics of robotics in six months, his first creation coming out a year afterwards. Of course, his first creation wasn't anything big, just a bug shaped camera nearly invisible to the naked eye, but the fact it was created by a five year old made it extremely impressive. When he was six, he started selling his inventions to the local police force before he eventually expanded to larger security companies, this being his source of money. Back home, he converted the basement into his personal laboratory. While small, it did its job, storing all the inventions he didn't sell.

The second thing she learned about her boy was that he was possibly the most stubborn individual she has ever met. When she first learned of his dream, she tried dissuading him from chasing after it, not believing such a thing could be achieved, but he continued anyways. When confronted with the problem of money, he easily found a way around it. Whenever one of his machines didn't produce the results he wanted, he simply shrugged his shoulders and didn't stop working on the project until it was perfected. He even began taking some martial arts classes despite having so many projects going on just because he believed the combat training would be useful to him. Going even further, he made sure to study the quirks of professional heroes and villains, making note of what they did right as well as possible ways to counter them. Such determination allowed him to create an Artificial Intelligence at the age of seven. When Izuku first introduced Inko to J.A.R.V.I.S, the name he gave the A.I which stood for Just A Rather Very Intelligent System, she nearly freaked out at how lifelike it was. Though robots and Artificial Intelligence units dominated society, none of them had any personality. J.A.R.V.I.S on the other hand seemed exactly like a person. While still bounded to the gadgets and doohickeys Izuku kept for himself, the A.I was capable of simulating human behavior without fault, practically serving as the young genius's only friend. A lack of a quirk prevented him from having any in the real world, in fact, it just made him a target for bullies. Thankfully, J.A.R.V.I.S seemed to fill in that void quite nicely. It also made sure Izuku didn't get carried away with work, something that Inko was grateful for. When he was nine, Izuku made a breakthrough in his work, creating his first armor. Titled Mark I, it was a clunky thing, but Izuku didn't care much about that for he was only going to use it to perform some tests before designing another version, one which could be used to fight crime.

"Uh, Izuku, are you sure this is safe?" His mom asked him, the two currently at a field where Izuku was testing the Mark I. He already determined its offensive and defensive capabilities, now all he was doing was making sure the final feature, flight, worked.

"Yeah mom, it's fine," Izuku brushed her off. "The Mark I can withstand hits from a tank so I'll be ok if I fall. If anything, J.A.R.V.I.S will simply eject me with a parachute if he determines the suit won't protect me from the fall."

Knowing she couldn't stop her little genius from testing dangerous machinery (she tried in the past but gave up upon learning how stubborn her son was), she simply watched as the suit of armor opened up from the front, allowing Izuku to enter inside.

"J.A.R.V.I.S, make sure Mark I's running smoothly before takeoff," Izuku ordered his A.I, it having a connection to the suit wirelessly.

"...All systems are fully functional," J.A.R.V.I.S responded. "You are clear for takeoff."

Hearing this, Izuku activated the suit's jet boots, it taking to the skies a second later.

"IT WORKS!" Izuku shouted in glee as the suit continued gaining altitude. "WOOHOO!"

Unfortunately, the suit couldn't stay airborne forever, it crashing back down to Earth almost a minute later.

"Ugh, looks like I'll need to make the suit lighter," Izuku groaned as his mother was frantically making sure he was alright.

0000

Upon turning twelve, Izuku made another scientific breakthrough, having created another super suit. Aptly titled the Mark II, the suit was a drastic improvement from the Mark I, both visually and functionality wise. Unlike the Mark I, the Mark II took a slimmer and more humanoid appearance, making it lighter and more agile. Despite it being smaller than the Mark I, the Mark II could lift twenty tons compared to the original's fifteen tons and it could withstand the power of a bomb. Flight has also been perfected, the suit's lighter weight and increase in power allowing it to stay airborne this time around. Finally, Izuku finally managed to figure out a way in which to power the suit for extended periods of time. The Mark I relied on a generator which lasted three hours before needing to be charged, the amount of energy required to power the suit reducing the generator's lifespan. To combat this issue, Izuku made his own energy source powerful enough to power the suit for days before needing to be recharged. Dubbed the Arc Reactor, the machine was a mini generator placed in the suit's chest, powering the entire thing. In addition to powering up the armor, the Arc Reactor could release bursts of energy, which Izuku called repulsor rays. To capitalize on this useful feature, Izuku kept the Arc exposed so he could fire powerful beams of energy from the hole. In addition, he had small holes in the suit's palms, each having a mini Arc Reactor of their own. The repulsor rays weren't his only methods of attacking, the suit having the ability to generate missiles, pulses of supersonic waves, and nets which electrify the target, but they were his pride and joy. He did create a new way of generating power after all, one which was eco-friendly and stronger than anything society has yet to produce.

With the creation of his first official suit, Izuku saw his twelfth year on Earth as his best to date, though the suit wasn't all that made it a great year. In addition to being a step closer to his dream, he ended up making his first human friend. Even though he had J.A.R.V.I.S and his mom, he would be lying if he said he didn't long for any social interaction that didn't involve him being picked on.

The day started off normally with Izuku and the Mark II going down to Gagen's Gear and Parts, a local Hardware store which sold the majority of the materials he needed for his projects. Whenever he went out to buy materials, he always had J.A.R.V.I.S autopilot the Mark II, him relying on the suit to do all the heavy lifting. Having the Mark II around also made the shopping go by faster since he could have it pick up one thing while Izuku picks up the other.

Of course, the suit always drew attention to him, as to be expected, but what he didn't know was that a new family moved right across the street from the store, their daughter being a huge science nerd as well.

"Looks like I've gotten everything," Izuku mumbled to J.A.R.V.I.S through an earpiece he kept on him at all times. "How's everything on your end?"

"I've acquired all the materials you've asked me to get," J.A.R.V.I.S replied. "Though I've run into a problem…"

"What kind of problem?"

"A girl about your age ended up spotting me and has refused to let me leave her vicinity. I was hoping you could speak to her, she seems genuinely interested in the Mark II."

"...Sure," Izuku stated. Social interactions weren't really his thing, but if what J.A.R.V.I.S was saying is true, then the two wouldn't be able to leave until he at least humored her. Walking towards the opposite side of the store, the boy was greeted with the sight of a girl with pink hair poking his greatest project in interest as she mumbled stuff under her breath.

"Hey, uhh…" Izuku lamely spoke, catching the girl's attention much to his surprise. "I see that my creation has caught your interest…"

"Wait? YOU'RE the one who made this sweet baby?" The girl spontaneously asked before the boy could finish his sentence, her eyes sparkling. "Amazing! I've never seen anything this high tech before! It even puts the pros to shame!"

"I'm glad you like it," Izuku bashfully replied. He wasn't used to being complimented by those who weren't his mother, J.A.R.V.I.S, or the people he sold his inventions to, so he was understandably somewhat embarrassed.

"How'd you do it? What metals did you use? How much can it lift? What can it do? What's with that thing in its chest? W-"

"Uh, can you please slow down? I can't keep up…"

"Sorry, it's just that looking at your baby really has me pumped up," the girl admitted. "So, how'd you make it?"

"Sorry, I can't tell," Izuku informed her, causing the girl to pout. There was no way he was giving his blueprints to a random stranger, he didn't even allow his mother to look at them. As an upcoming hero, he knew withholding information was important, otherwise, someone could use it against him.

"Aw, can you at least tell me what that thing in its chest is? If I had to guess, I'd say it's some sort of generator or energy source, but I've never seen anything like it..."

Izuku smiled upon hearing her guess. The Arc Reactor's purpose wasn't something most were able to guess immediately. "Heh, you're actually right. The thing in its chest is what I call an Arc Reactor, a small machine which generates more energy than anything we have now. I invented it myself."

"Wow, and here I thought I was the only one our age who could invent. I have to know your name, mine is Mei Hatsume."

"Izuku Midoriya."

"Well my fellow inventor Izuku, I was wondering if you could help me with something. You see, I initially came here to buy parts for one of my babies which keeps blowing up in my face, but I was obviously distracted by your magnificent specimen of a baby. Could you help me figure out what the problem with my baby is?"

Upon being asked this, Izuku's mind began spazzing out. The boy was never invited to hang out by anyone his age, much less a girl. He honestly would be a bit out of his element. However, he knew he wouldn't have the chance to speak to a fellow inventor again if he dismissed the girl. Also, heroes were supposed to help others, what kind of hero would he be if simply ignored her?

"S-sure," he almost squeaked. "L-lemme just pay for my stuff and let my mom know where I'm going and we'll be all set."

"Hooray!" In one swift movement, the girl wrapped her arms around her new friend, grabbing him in a surprise hug. Of course, Izuku being the person he is, became a blushing mess as a result.

0000

That one encounter ended up sparking a friendship which has lasted two years and counting. After Izuku fixed her doohickey, Mei practically begged him for his contact information, something he ended up giving her. She'd then go on to ask him to co-create some 'babies' as she calls them, causing them to become closer. To Izuku, Mei became his first and only friend. To Mei, Izuku became the only person who understood her desire to invent. Mei didn't even care that Izuku didn't have a quirk, something he was surprised by. To her, it made him far more impressive. Sadly, the only times they were able to hang out was on the weekends and on the holidays, both attending different schools. Granted, both could easily enter college now if they wanted, but there was one thing which prevented them from doing so, entrance to U.A Academy. U.A Academy was an elite high school which has produced not only some of the best inventors to ever exist, but some of the top heroes as well. They even taught All Might himself. Going to the same school the number one hero himself went to wasn't something the two were going to pass on, especially Izuku. To the boy, going to U.A would help him become the best hero he could be.

"All right, as you all know, you're all reaching the end of middle school," Izuku's teacher middle school teacher stated, seemingly finished with whatever it was he was talking about earlier. He never bothered paying much attention to the lessons taught, having learnt them himself. He preferred to use this time to brainstorm ideas for future suits of armor or text Mei. "Now's the time you all think about your futures. Eh, who am I kidding? All of you are planning on becoming heroes, correct?"

Upon saying that, most of the students began cheering in affirmation, some of them even displaying their quirks in a non-destructive manner.

"Hey teach, don't lump me into the same category as these crappy side characters," a boy with ash blonde hair scoffed. "I'm off to be the best damn hero you've ever seen."

Izuku's classmates began mumbling to themselves upon hearing this all while Izuku secretly rolled his eyes. The boy, Katsuki Bakugo, was someone who Izuku was familiar with, the two having practically grown up together. Izuku always admired his determination, one which never seemed to diminish. Sadly, that's the only positive thing the boy could say about him. Katsuki was his number one tormentor, constantly looking down on the genius due to his lack of a quirk. His attitude was also as explosive as his quirk, which was ironic since his quirk allowed him to create explosions from his hands. Basically, he wasn't fit to be a hero mentally, but he certainly had one of the, if not the strongest quirk in the school.

"Ah, right, you're applying to U.A correct?" His teacher asked the boy, surprising most of his classmates. U.A Academy was considered to be the best hero development school in Japan. The chances of anyone getting in were slim, yet this didn't seem to faze Katsuki, the boy having a smirk on his face.

"Damn right I am, I even aced the mock test!"

"Wait, aren't you applying to U.A as well Izuku?" His teacher asked him after hearing Katsuki's response, painting a large target on his back. Upon hearing this, his classmates began laughing at him.

"Really? Isn't he quirkless? How does he possibly think he can get into U.A?"

"Deku," Katsuki growled, not liking the fact the boy was applying to the same school as him, Deku being a nickname the boy gave him out of mockery. Deku was a word meaning useless, and Katsuki latched onto it, using it to mock the boy for his lack of a quirk. Though it initially bothered him, after creating the Mark I, Izuku practically ignored the taunts thrown his way. He had better things to do than humor them. However, that comment left by his classmate somewhat irked him.

"I'm applying to the support course," Izuku told the class. The support course at U.A was designed to teach upcoming engineers how to hone their talents. Students from this section weren't limited to support though for they were allowed to take some pro hero classes if their grades were high enough. Even if they choose not to do so, they still have the option of taking the Hero Licensing Exam, an exam which determines whether someone can become a pro hero or not. As only individuals with quirks are allowed to take the hero classes, Izuku's plan was to go through the support course before taking the Hero Licensing Exam, the test being open to quirked and non-quirked individuals, though the latter group has yet to have a member pass. Izuku practically made it his mission to be the first quirkless person to pass the exam upon learning this. "You don't need a quirk to get in."

Everyone shut up after that, not really having a response to what he said.

0000

"Hey Mei, have you thought about what you're going to make for the entrance exam?" Izuku asked his friend as the two ate at a local diner. All courses at U.A have an exam one must complete to be granted entrance. For those aiming to be in the support course, they need to present one of their inventions to the staff. Funny enough, despite Izuku having the Mark II, Arc Reactors, and J.A.R.V.I.S he could use as his project, the boy honestly didn't know what to do for his presentation. Now, he could use on of the three inventions mentioned, but U.A had the right to use or reproduce any of the inventions used in the presentation, something which discomforted him. To avoid such discomfort, Izuku was aiming to create something he was comfortable sharing with them, but as of this moment, he had nothing in mind. While he has six months to think of something, building any sort of machinery takes time, time which was limited at the moment.

"The entrance exam? I'm thinking about upgrading my anti-gravity boots and showing them off. Why?"

"Just trying to get motivation to make something."

"What about the Mark III?" The girl asked, the Mark III being the newest model of armor Izuku was working on. Compared to the Mark II, the Mark III was to be twice as strong, much more durable (especially against intense heat and cold), faster, and have more portability upon being completed.

"You know full well I can't give U.A my armor. Also, there's no way it'll be completed by then. Hey, if you were a top notch superhero, what would you want?"

"Obviously a way to make fighting crime easier," Mei immediately replied, not giving her answer much thought.

"A way to make fighting crime easier," the boy mumbled to himself. "How could I do that? I could make an offensive or defensive weapon of some sort, but that's what almost everyone else is doing. I need to be creative. Hm...maybe I can create something which nullifies one's quirk, but could that really work? I mean, the hero Eraserhead has the ability to erase someone's quirk while looking at them, but I'm not sure how to replicate that ability. Wait, if I can't erase quirks, how about I make something which could amplify a quirk? That can work…"

"Mei, I think I found out what I'm making."

0000

The six months went by rather quickly for Izuku as he devoted most of his time and energy into his power amplifier and the still incomplete Mark III. The power amplifier was quite hard to build, for nothing like it existed beforehand. Sure there were gadgets which allowed someone to control their quirk better, but it never did anything to the strength of the quirk itself. After many failed attempts, Izuku finally managed to make something which powered an individual's quirk by fifty percent. A small bracelet, the machine would inject the individual with a small needle before releasing a pulse of energy. Said energy would give the user a spike in power for a few seconds. As of right now, the power amplifier was only meant to be used in emergencies, but Izuku was more than confident it would guarantee him a spot in the support course.

"Out of the way Deku!"

Looking behind him, he saw Katsuki walking towards U.A, today being the day the entrance exams were being held. Not wanting to engage in unnecessary conflict, Izuku simply moved to the side, allowing the boy to pass by him with no difficulty.

"Thank goodness we're not taking the same exam," Izuku mumbled to himself. Having a powerful quirk, Katsuki was blessed with the chance at making it to the hero course. Though somewhat jealous, Izuku reminded himself that entering the hero course wasn't necessary to be a hero: just getting in the school was good enough for him.

Shaking his head, Izuku decided to enter the school as well, not only wanting to get the exam over with, but also wanting to see his best friend again. She was in the building after all, having arrived an hour before he did.

0000

The presentation, while filled with some stuttering on Izuku's part, went off without a hitch. The judges, all pro heroes, loved his power amplifier and gushed about all the possibilities it brought to the table when it came to improving the lives of pro heroes. From what he could tell, Mei's went smoothly as well, though she had the advantage of not stuttering as she spoke.

It would be a week before either one of them got their results and to be honest, both were scared. Yes they wooed the judges, but there was the possibility of one of them making it while the other didn't. The lineup of inventions this year surprisingly provided no stinkers, each being useful in their own way.

Eventually, the wait would be over as Inko ran to her son, handing him a letter sent to him by U.A. Immediately locking himself in his room, the boy simply stared at the letter for a few minutes before working up the courage to read it (only those accepted to the hero course got holograms). Skimming through it, the boy's eyes became watery as a small smile formed on his face.

"I made it. I actually made it. I'm now closer to my dream. Watch out world, for here I come…"