Now this one will be an interesting and unusual one. This is basically a crossover between Girl Genius and My Hero Academia, though it's more of the latter than the former. While elements of Girl Genius will be in the storyline (the Spark, Izuku is descended from Sparks who fled to the world of My Hero Academia to escape the Other), the focus is more on Izuku being a hero with the Spark...along with One for All.

Also, for any fans of Katsuki, I'm gonna bash the everloving fuck out of him. He's a bully and an arsehole with no redeeming features this early on in My Hero Academia. FFS, he even incites Izuku to commit suicide. Izuku will be less of a wimp and less optimistic than in canon, but he will still be, overall, the same good-natured kid he is.

Anyway, I hope you enjoy.

EDIT: After looking back on this, I've decided to revise this story. I'll post the new initial chapters later. It felt awkward, especially with how All Might was going to give One for All to Izuku, but in my new version, there's more logic to it. I'll post the new version of the first chapter soon...

MAD SCIENTISTS CAN BE HEROES TOO (ORIGINAL)

CHAPTER 1:

BREAKING THROUGH

"YOU FOOLS! I'LL DESTROY YOU ALL!"

This was an unexpected utterance, to say the least, not least because of who was saying it. Okay, in hindsight, it was a fair assumption to say what triggered this outburst, but it was still a shock. It was like hearing a mouse suddenly emit a roar like a lion(1).

After all, it was Izuku Midoriya who emitted said roar. And his meekness often made a mouse look strong by comparison.

Izuku Midoriya was Quirkless. In other words, he was part of the 20% of the world's population who apparently didn't have a power of some sort. And yet, despite this, he had aspirations to being a hero.

Unfortunately, one of the most persistent naysayers was an acquaintance and former friend by the name of Katsuki Bakugo. Katsuki was, frankly, a bullying arsehole of the highest order who had a Quirk allowing him to sweat nitroglycerine and explode it safely…for him, anyway. However, Katsuki had just used said power to destroy his notebook. And then, he had taunted him, suggesting that Izuka commit suicide, and then maybe he might get reborn with a Quirk. And that had been the final straw.

Imagine a dam bursting. Imagine all that water bursting forth and sweeping away everything in its path. Imagine the sheer force and power of all that water, held back by the designs of man, only to be suddenly unleashed. And imagine that, sweeping through the mind of a teenaged boy, the fury and the wrath.

Except, even with it being a raging flood, there was something being shaped in its wake that was more orderly than what a flood did. Things became sharper, clearer. Izuku was always a smart boy, with his highest grades being in the sciences and mathematics (yet another thing for Katsuki to bully him about), but it felt like his thoughts were going to the next level, fire burning along his neural pathways. The fire of Prometheus.

What was even more unsettling was that, as the floodwaters began to sink, even if the turmoil they left still boiled and raged, he looked at Izuka, and could see, very readily, the weakpoints of the human body. It was like he was the Terminator, and saw little arrows pointing here and there, telling him how to take down the foolish bastard who had cruelly taken his notebook away from him. A few blows here and there, and Katsuki would be sprawled on the floor of the classroom, broken. If not dead.

He recoiled from that. Dead? Over a notebook? As he flinched inwardly at his own thoughts, Katsuki and his posse were staring at him in bemusement. "Uhh, Katsuki? What's with Deku?"

Katsuki, for the first time in a while, didn't have an angry glare or a contemptuous sneer or smirk on his face. Instead, he had a look of surprise and shock that looked alien to his face. "…I dunno. Maybe Deku's finally gone round the bend at the thought he's a Quirkless loser," he said, regaining his usual contempt, before swaggering out the door.

Round the bend? He'd never felt more sane in his entire life. He didn't care what the others staring at him thought, either. No…all he cared about was that he knew, no matter what Katsuki or the others thought, mocking him, he WOULD be a hero…

The strange madness had died down, the raging inferno (wow, he was changing elemental metaphors from water to fire) dying down to a gentle blaze. The spark was still there. No, it deserved capital letters. The Spark.

His vision seemed keener and clearer now, his perception sharper. He could see how things worked around him, buildings, machines, people…and he found them wanting. He wanted to take them apart, put them back together, deconstruct them and reconstruct them so that they would be better than ever.

It was only his senses being sharper and clearer than ever that he was able to sense the thing emerging from the manhole that he had just stepped over. He heard a faint slurping noise, and then, a distorted voice murmuring, "A medium-sized body to hide in…"

Izuku dodged just in time to avoid a dark green thing lunging at him. He yelped in surprise, dodging attack after attack. "Hey, stop dodging, kid! Calm down! I just wanna borrow your body for a bit! I mean, it'll only hurt for…45 seconds? And then, it'll all be over…"

"Go away!" Izuku yelled, even as his mind went into overdrive, trying to figure out weak points. The creature in front of him was an amorphous mass of dark green sludge with eyes and jagged teeth.

"Pfft, ain't gonna happen kid. Come on, I need your help. You'll be a real hero, saving me from him. Never thought he'd be in this town…"

As Izuku dodged another attack, he wondered who he was talking about. He then punched at the sludge man's eye, and caused him to screech. But then, the manhole cover the villain had oozed from burst open. "Never fear, kid!" roared the figure who leapt from it. "I have arrived!"

Izuku gaped, and the sludge villain whirled to face the newcomer, and swore vehemently. "All Might?" Izuku whispered.

For it was, indeed, All Might. A big burly bear of a man with huge muscles, blonde hair swept up into two antennae-like points, his face almost always in a wide grin, his eyes always in shadow. "TEXAS SMASH!" All Might roared, hitting the sludge being with a powerful blow that stunned him.

All Might then turned to Izuku. "My apologies for getting caught up in that, kid. This is a pretty unfamiliar part of the world to me, and letting him get away is not a mistake I would have made, normally. Still, thanks for distracting him." With that, the burly man began gathering the stunned sludge man and putting him into a large soft drink bottle.

Izuku tried his best not to fanboy out at his idol, the top hero in the world, being right there in front of him. All Might, the best known and mightiest hero. Instead, he gathered his thoughts, and asked, "Umm…sir?"

"Call me All Might, sir makes me feel old," the large man said with his habitual grin. "And if it's an autograph you want, I'll be too-happy to oblige once I'm done."

"Oh, that'd be great…but that's not what I wanted to ask you. I wanted to ask you…a serious question. About…about what it means to be a hero." Izuku went over and helped him gather the stunned slime man.

All Might may not have lost his grin, but there was something about his body language that changed, making him seem more solemn. "…Why do you ask?"

"…I was born without a Quirk. Or so I thought. Can a Quirk manifest itself in its teens?"

"…Well, that's rare, but I wouldn't say it's impossible. But you believe that you are, or were, Quirkless?" All Might asked, finishing his messy task.

"Yes. But…I have to ask…can someone born without a Quirk…can they become a hero like you? Only, I've always been picked on, and yet, maybe I think that saving people is the coolest, best thing I can do. You save all those people with that fearless smile of yours, and that's why I want to be the strongest, just like you."

All Might then emitted a sad chuckle, before he came over. "You said you wanted my autograph, kid?"

Izuku nodded, and pulled out the tattered notebook, what he salvaged after Katsuki destroyed it. All Might scrawled an autograph, only for him to convulse, and grimace, a speck of blood spurting from his mouth. "No! Not now! I…"

And then, he changed.

To Izuku's amazement, standing in front of him, in place of the burly, grinning All Might, was a skeletal figure, a grotesque lanky scarecrow with deep-set eyes and a painful grimace on his face. "Umm…are you okay?" Izuku asked, not sure whether this man was an impostor or something.

The man gave a pained chuckle. "No, I'm not. Before you ask, I'm All Might. And don't yell or anything. I'm lucky my transformation reverted here, and not on some crowded…gurk." This last syllable was accompanied by a stream of blood from the man's mouth, who wiped it away. "It's a bit like how some people hold in their beer belly at a pool. A fearless smile, huh? Kid, you're seeing the real me, though I don't want you posting about it on social media." He sat down on a nearby bench, before lifting up part of his now-baggy shirt.

Izuku stared in genuine horror. It looked like a massive crater, surrounded by lines of surgical stitching, a grotesque shatterpoint of scar tissue. "What happened?" he asked in understandable horror.

"A villain happened, five years ago. My lungs nearly gave up on me, and I had to have my stomach removed. As you can guess, it didn't really have the best effect on my health. I can really only do my hero work for maybe three hours a day."

"Five years ago? Was it Toxic Chainsaw who did that to you?" Izuku asked, recalling the fight.

All Might, if that was who he was, shook his head. "A lowlife like him couldn't have done this. I asked for it to be kept under wraps. I think you can understand why. A symbol of peace who saves the day with a smile can never be seen to fall to evil. I smile to stave off the pressure and fear I feel as it creeps up on me, threatens to become overwhelming. A professional hero must be willing to risk life and limb. It's not for the faint-hearted, or for those without the power to fight on the level of villains." The scarecrow shook his head. "I'm sorry to tell you this, kid. If you really think you've got a Quirk that somehow awoke later in your life, then maybe you've got a chance. And anyway, there's always being a police officer. I mean, Villain Custody Officers may be the butt of jokes, but in truth, they're good people who do good work."

"…So that's it? Just because I may not have a Quirk means I don't have a chance?" Izuku asked, stifling his anger and shame at being told off by his idol.

"…Kid, it's not wrong to dream, but you need to be realistic. You can do great things in the world without having a Quirk…" A thought seemed to occur to All Might, before he asked, "Kid…are you truly willing to risk your life to help others?"

"…Yes."

"…Even those who bullied you? Even villains?"

"…Yes."

All Might peered at him with his beady little eyes, sunk in those sockets. They felt like they were peering into the depths of his soul. After a moment, he said, "Even with that hesitation, I can see your conviction. And you acted, despite having no Quirk. I saw the aftermath of your punch just as I exited. And you helped me gather him up. Not afraid to stand up for yourself or do dirty work, even with no Quirk, unless you do have one."

"I don't know. I mean, the doctor we saw when I was young…he claimed I wouldn't have one…and yet, earlier today…well, it's like I could see things…how things work. How they're put together. How to make them better. It felt like I went a little mad for a while."

All Might looked thoughtful. He peered into Izuku's eyes once more, before he nodded. "Kid, I don't think that's a Quirk. Actually, I have an idea." He handed Izuku a phone. "This got broken earlier. I want to see if you know why."

Izuku, almost by instinct, despite having never really tried to repair a mobile phone, instantly did so, disassembling it with dextrous, instinctive movements he was certain he had never used. "Well, there's your problem. This bit's come loose, and I don't think this bit is meant to be burnt out. Now, I put this here, and the other bit there…ooh, and I can improve this…"

Fifteen minutes passed, with Izuku humming gently as he worked on the phone, All Might looking on, occasionally drooling blood from his mouth. Then, he was done, and handed it over. The emaciated hero looked at it, activated it, and blinked. "Huh. My reception's the best it's been in ages. And you've never tried to do that in your life?"

"No, never. I mean, I like science, math and technology, but I've never tried to repair a smartphone before. Never even knew how."

All Might grinned painfully. "Then I think I know what you actually have, kid. In fact, I think it'll be just as good as a Quirk. You, kid, have the Spark."

CHAPTER 1 ANNOTATIONS:

Okay, so it doesn't happen like in canon. All Might's only considering giving Izuku his power, rather than deciding then or there, but that's because Izuku didn't make him drop the bottle by accident, and allowed that slime guy to go on another rampage.

1. This is a very oblique reference to a comedy film starring Peter Sellers, The Mouse that Roared. Which also starred a certain William Hartnell, aka the First Doctor from Doctor Who.