My Hero Academia: The Hidden Pulse

The crisp morning air was still and quiet, save for the occasional hum of drones hovering around Kairo. He stood in a training field, his breathing slow and steady. The session had already lasted over an hour, and his muscles were beginning to burn from the repeated motions.

Mei, ever the enthusiastic tactician, had added an extra layer to their usual drills—illusionary projectiles mixed with real ones.

"This test isn't about raw speed," Mei explained, adjusting a control panel. "If you flinch at an illusion or dodge too late, you'll either get hit… or waste movement."

Kairo flexed his fingers, mentally replaying his past battles. His fight with Todoroki and Kenta had exposed weaknesses in his combat style. While his speed and power were solid, his dodging relied too much on reaction time, not predictive movement.

He needed to refine his awareness.

The test began. The drones launched their attacks—real metal spheres mixed with illusionary ones.

Kairo dodged the first few effortlessly, shifting his weight just enough to avoid them. But then—an illusionary attack came from his left. His body instinctively flinched—opening him up to a real projectile that slammed into his ribs.

"Tch…" He exhaled sharply.

Mei smirked. "You flinched."

Kairo clicked his tongue. It wasn't about being fast—it was about distinguishing what was real from fake without hesitating.

Again.

Another barrage came. Kairo focused—not on his eyes, but on the airflow, the sound, the vibrations through the ground. Instead of flinching, he adjusted his posture just enough to let an illusion pass through him.

No wasted movement.

Another real attack came. This time, he pulsed a shockwave through his foot, subtly shifting his momentum mid-dodge—just enough to evade.

Better.

By the time Mei shut off the drones, Kairo was breathing hard, sweat dripping down his forehead.

"Not bad," Mei admitted. "Still needs work, though. You're improving, but you're still relying on instinct too much. You need to predict, not react."

Kairo wiped his forehead. "Yeah… I'll get there."

Mei studied him for a moment, then grinned. "I gotta say, though—watching you push yourself like this? It's kinda fun."

Kairo scoffed but smirked. "Glad I can entertain you."

With training done, they parted ways—but Kairo's mind was still racing. He had learned a lot from this session. But real combat was always different.

And soon, he'd be facing something far beyond training.

By the time Kairo arrived in class, his muscles still felt warm from the morning session. He noticed that some students were still talking about the previous battles.

"You and Todoroki really went at it, huh?" Kaminari said as he stretched. "That was one hell of a match."

Todoroki, sitting a few seats away, remained silent, but Kairo noticed his eyes flicker toward him for a second. There was something different in his gaze—not just the usual cold detachment.

Resolve?

Kairo shook the thought away. There wasn't time to dwell on past fights.

Aizawa walked in, looking as sleep-deprived as ever. "Alright, listen up. Today, we're going to U.S.J. for a disaster training exercise. Get changed and meet at the bus."

The class immediately perked up.

"Rescue training? Sounds fun!" Kirishima grinned.

"Finally, something that's not just sparring," Momo said with a nod.

"Rescue training?" Kairo muttered under his breath. It wasn't something he had focused on before. He had spent all his time improving his combat ability—but saving lives was just as much a part of being a hero.

This would be new territory.

Arriving at U.S.J. – A Heavy Atmosphere

The Unforeseen Simulation Joint (U.S.J.) was massive—a domed structure replicating various disaster scenarios. Inside, they were greeted by Pro Hero Thirteen, who stood before them in their signature black-and-white spacesuit.

"As heroes, your duty isn't just to fight villains," Thirteen explained, hands gesturing to the different zones. "Many situations require you to save people first and foremost. Today, we'll be testing your ability to handle rescue scenarios—floods, fires, landslides, and more."

Kairo listened, but something felt off.

His instincts—honed through training and battle—were tingling.

It wasn't just nerves. It was… something else.

His eyes flickered across the room.

Izuku looked excited but focused. Bakugo seemed disinterested. Todoroki was deep in thought.

And then—

A sharp shift in air pressure.

Kairo's heart skipped a beat.

At the center of the facility, a dark mist began to form. It expanded, warping and twisting into a massive portal.

Then, they emerged.

Villains. Dozens of them.

For a second, no one moved. Disbelief. Confusion.

A deep, distorted voice cut through the silence.

"Ah… so these are U.A.'s promising students?"

The mist coiled and twisted, revealing a shadowy figure. Kurogiri.

Behind him, figures of all shapes and sizes stepped forward, each radiating hostility.

"Wait… this isn't part of the exercise," Jirou muttered.

Kairo's fists clenched. This wasn't training. This was real.

Aizawa reacted instantly. His scarf lashed out, taking down the first wave of attackers.

"Thirteen! Get the students out of here!"

But before anyone could move, Kurogiri spread his mist.

Dark tendrils shot out, engulfing the class in a split second.

Kairo felt the ground vanish beneath him.

He reached out, but the mist swallowed him whole.

And then—

Everything changed.