1. Prologue

Midoriya Izuku is a weak child. Why? Two reasons: Firstly, he was born with a weak immune system. Because of this, he has gone in and out of clinics and hospitals since young. As for the second reason: when he turned four, his quirk emerged.

"Attraction of metal objects, I guess." is his reply upon receiving questions about his quirk. "My mom has the quirk to pull small things toward her. I think it's a slight variation of that." he scratches his cheek bashfully, "It's kind hard to use, though. My head hurts when I use it too much and I get a migraine."

As he grew up, he began to use his quirk more, hoping it would become stronger as he gets older. And yes, in fact, he had built up a fair amount of endurance for it. Soon, he could use his quirk for daily things like grabbing spoons or hammering nails. But picking up heavy things like cars and fridges were still incredibly out of the question.

But then, something happened when he and Bakugou Katsuki were seven.

They were playing basketball with a few of their friends. And honestly, they were having a very fun time, even if Izuku was horrible at the game. Katsuki and a friend were playing roughly, enjoying themselves by being super competitive. Izuku and the other friend, Sakaki, stood by trying not to get killed by the brawling brats.

And by some freak accident, they crashed into the portable basketball hoop. It toppled over and headed straight for Sakaki. The boys froze in surprise and oh shit, too sudden for them to figure out what to do.

Impulsively, Izuku activated his quirk. The whole structure floated ten feet above the air, and Izuku focused really hard on keeping it there. It swayed at a single bit of distraction.

"Wai- You idiot!" Katsuki, snapping out of initial shock for priorities, dragged Sakaki away from danger. "Deku!" he yelled, "Let it go!"

And Izuku did exactly that. He let it down, forcing himself to do it slowly so it would land safely. He was sweating profusely, struggling to catch his breath as he fell to his knees. Making sure Sakaki was uninjured, Katsuki made his way over to Deku.

Izuku immediately flinched and held his head, feeling the pain of the migraine. It hurt more than usual. A lot more, and it wasn't stopping. In fact, it was getting even worse. He squeezed his eyes shut, his hand holding his head, rubbing his temples at an attempt to ease the pain-

"Deku, you alright-" Katsuki's voice caused his brain to twinge, the loud volume hurting his ears.

He tried to move his head, and decided against it as he felt a sharp throb at his head. He suppressed a moan at the pain. He lay down on the floor, his head on the ground as he struggled to remember how to breathe.

"Hey! Call an adult!" Katsuki's panicked voice began ordering around, but Deku could no longer hear.

The pain was growing, the ache was worsening, and every fiber in his being began screaming out in agony- oh my god make it stop it hurts it hurts it-

He coughed, sending another waves of spasms across his body. He felt a pang in his head at each movement. The cough was followed by another, and another, and another, and another- And he began tasting iron in his mouth- blood. He was freaking coughing out blood.

He felt himself being lifted up- it sent another shockwave of spasms across him, which he mentally cursed at -and he felt himself moving. It was a rough ride, as each step whoever that was took hurt his body and burned his lungs and made his head ache.

He doesn't know when he'd fallen unconscious, but when he woke up, it was two days later.

Since then, he dubbed the episode a Rebound. The consequence if he were to overuse or abuse the power of his Quirk.

After each Rebound, he gets a little weaker physically. It was extremely likely that he'd shortened his lifespan. He got sick a lot more often, and he'd often cough up blood. He made frequent visits to the hospital and barely made the attendance cut in school. He was even banned from Physical Education classes.

He had to give up on his dream of becoming a hero. It wasn't a forced decision, really. It was just that-

When he'd woken up that day on a hospital bed, he saw his childhood friend in tears, pleading for him to just not fucking do that again, all his passion and dreams just melted away in guilt. Seeing his mother crying and sobbing in worry just discouraged him further.

He's made up his mind. He wasn't going to become a hero. He would find some other way to help the society. A way that didn't involve going into dangerous battles and risking his life. A way that didn't involve giving his mother heart attacks and causing his childhood friend to worry.

And that was when he'd found out about the Support Course in UA. The Course that focuses on aiding the heroes and creating the vital weaponry and equipment to help them out. It sparked a new interest in Izuku.

"Kacchan, I'm joining the Support Course in UA!" he had made the promise, "So you get into the Hero Course too, okay?"

This is the story of how Midoriya Izuku became the best ever Support Hero.