AN: Sorry for the late chapter, I was playing skate
—Development Studio—
"HAHAHA!" Renji laughed manically while holding up a small syringe in his hand.
"BEHOLD! My greatest creation!" He yelled with a sinister grin.
His shouting caused many of the others in the studio to look his way. Just what he could have accomplished within the hour?
Hatsume ran up from her station to check out what Renji was doing.
On his table were multiple small canisters, all of which were empty. Earlier, when Renji arrived, he had placed them on his desk so he could empty the nanobots inside and modify their use.
It would have been dangerous to do so prior to coming to U.A. Here, he had access to the private network, advanced tools, and a supercomputer of Nezu's own design which was heavily inspired by his own super intelligence quirk.
"Ooo~" Hatsume peered at the syringe in his hand. Within the syringe were the countless nanobots that Renji had made while at Shinkou Academy. They had been initially used as weapons in order to chew through metal and wiring, almost like a swarm of bugs.
However, using his new toys, Renji was able to not only modify their use, but also reinforce them and upgrade them for peak performance.
"Nanobot tech?" Hatsume asked, clearly interested in how he even got the funding for that kind of project.
"Exactly!" Renji would have explained further, but he was much too excited to say more. The once calm and reserved Renji had been overridden by a more egocentric and determined persona ever since he arrived on the U.A. campus.
And who could blame him? He was in one of the most advanced labs in the world working on his most prized creations.
"So, what does it do?" Hatsume asked, eyes zooming into the syringe with her quirk.
Other Support Course students walked over to Renji's corner, eager to see why a Hero Course student was causing such a racket.
"Hehehe—" Renji laughed uncontrollably with a manic smile that stretched across his entire face.
"WATCH AND LEARN!" He shouted to the crowd as he jammed the syringe into his neck and pushed down hard, sending all of the nanobots into his body.
"Woah!" Hatsume yelped and the crowd flinched back in surprise.
A few of the students gasped in shock while others whispered animatedly.
"This Hero Course guy is insane!"
"Is he even allowed to do this?"
"I swear he just got here like half an hour ago!"
Rushing through the room, Power Loader shoved past the growing crowd to get to Renji. "Move out of the way, let me through!"
Even if Renji wasn't a support course student, that didn't mean he wasn't under Power Loader's supervision. If anything were to happen to Renji, he'd be kicked out of the school.
Well, maybe not kicked out, but he'd seen the look on Nezu's face when he talked about lending Renji his supercomputer. It was borderline psychotic!
Renji twitched as he fell to his knees, the nanobots rushing through his body under his strict command.
The instant the plunger hit bottom, Renji felt the swarm burst into his bloodstream like ice and fire all at once. His vision flickered, and for a moment it felt like his body was humming at two different frequencies.
He clenched his teeth as the nanobots fanned out. He didn't have to see them to know where they were going.
A surge hit his legs first. His quads and calves spasmed, fibers twitching faster than they should, like someone had rewired the coils of a spring and cranked them too tight.
The bots dug into his muscle fibers, syncing with the calcium pumps. Every contraction felt sharper, like his body had learned a new language of speed overnight.
Then came the nerves. A hot buzz ran down his spine, into his arms, through his fingertips.
The nanobots aligned themselves along his motor neurons, shrinking the gap between thought and motion. He flexed his hand and nearly flinched at how immediate it was. It was like the muscle had moved before he finished deciding to.
A different kind of burn spread through his chest. His heart hammered, every beat flooding his veins with more oxygen than before.
The swarm was tinkering with his blood, pushing more fuel into the system. His lungs drew in air greedily, expanding like bellows under invisible hands.
And then came the pressure. A cluster wrapped tight around his chest and stomach, regulators locking into place. A failsafe.
He could sense it holding back the flood, preventing him from tearing himself apart with his own strength.
Renji staggered, sucking in a sharp breath, sweat dripping down his temples. His whole body was alive for the first time, vibrating with potential energy.
Despite himself, he let out a small giggle of delight.
It was working.
—
Power Loader knelt by Renji as he twitched incessantly, before looking up at the crowd with a look of anger.
"What's going on here?!" He shouted, looking around. "Do any of you know what he just did?"
The students all shook their head, telling their teacher that they all came over precisely because they wanted to know what was happening.
Meanwhile, Hatsume moved over to Renji's station which was still hooked up to Nezu's private network and his supercomputer.
"Oh my god." She whispered, reading through the notes and the simulation reports on Renji's project.
Suddenly she laughed out loud, turning to stare at Renji's twitching body in disbelief. Even collapsed on the floor, Renji still had a manic grin on his face. "This guy's crazier than me!"
—
Eventually, coming off the high, Renji was finally able to move. Slowly, he pushed himself off the ground. While the nanobots in his system would help him adapt to his new body, it would still take a moment for everything to work out.
"Phew!" Renji let out a breath as he stood up, still stabilizing. "What are you guys all looking at?"
Power Loader could only sigh in relief, watching Renji stand up perfectly fine was the greatest thing to happen to him since he got a job at this school.
"You okay, kid?" He asked, noticing that Renji didn't seem too out of it, even though he had been convulsing just a second ago.
"Nope!" Renji replied, turning to Power Loader with a grin. "I probably gave you quite the scare, didn't I?"
He chuckled along, even if Renji had almost given him a heart attack, he couldn't help but see the humor in it. "You sure did."
Renji flexed his hand, curling and uncurling his fingers with a look of fascination. The motion was extremely crisp, like the morning air during winter.
The crowd of students hadn't dispersed. If anything, more of them had gathered. Whispers rippled through the group, half awe, half horror.
Power Loader waved them back with a sharp motion. "Alright, show's over! You've all got your own damn projects to work on. Don't make me repeat myself."
Reluctantly, the other students scattered, though more than a few kept sneaking glances at Renji as they returned to their benches. Hatsume, of course, didn't move an inch.
Renji rolled his shoulders, then crouched. "This feels amazing," he muttered. His body buzzed with potential, like a coiled spring begging to be released. "Like I could—"
He kicked off the ground without warning.
The floor cracked under the force of his launch. For a split second, Renji was airborne, shooting upward like a cannon round.
His head brushed the ceiling before he twisted midair and landed hard, skidding back into his corner of the studio.
Gasps rang out across the room while Hatsume clapped like a lunatic. "YES! DO IT AGAIN!"
"Perfect," Renji breathed, rolling his ankle, then kicking his leg in a blur too quick for the eye to follow. Not a twinge of pain, not a hint of strain.
Power Loader gawked at him. "Did you inject some kind of enhancement? Is there no adjustment time? No feedback loop? You're just… fine?"
Renji smirked, tapping his temple. "That's the point of simulation, sensei. I've spent years on this project. Every cell, every synapse, every fluctuation in hormone response.
I just needed access to Nezu's resources to make sure everything went swimmingly. By the time I stuck the needle in, the outcome was set in stone."
Power Loader's jaw tightened. "You're telling me you just rewrote your own physiology without a single live trial beforehand?"
Renji grinned wider, brushing a bead of sweat from his temple with the back of his hand. "I know my body better than even people with quirks that help with analyzing anatomy."
Power Loader rubbed the side of his helmet, exhaling through his teeth. "Kid, you don't seem to understand. You just performed something most governments on Earth would call a war crime."
His voice lowered, edged with real steel. "One slip and you could've torn yourself apart from the inside out."
Renji only shrugged, shoulders rolling loose, casual. "And yet…" He raised his hand, snapped his fingers. The sound was sharp, too sharp, sounding almost like a whip crack.
"I didn't. Because unlike most of the world, I don't need to gamble. I've been refining this system since I was ten."
Power Loader's visor tilted, unreadable. "…You're insane."
Renji chuckled, tilting his head like the comment amused him. "Insanity is just foresight the rest of the world hasn't caught up to yet."
The tension broke when Hatsume snapped her head after reviewing more of Renji's data from the console.
"Waitwaitwait. Your bots got a full regulatory matrix, synchronized at the mitochondrial level! You built a feedback governor right into the swarm! That's why you didn't explode!"
Renji smirked, sliding his hands into his pockets. "Of course. I'm not here to die testing my toys. I'm here to win with them."
The room had gone silent again. Students exchanged uneasy glances. Half of them wanted to applaud, the other half wanted to run away from the monster sharing the same air as them.
Power Loader finally shook his head, muttering under his breath. "Nezu, you mad bastard. Did you even know what you were inviting into my lab?"