One Punch Man: Heroics Start with Dual Kamui

That single, casual remark from Shinji pushed Carnage Kabuto over the edge. With a furious roar that rattled the walls, he lunged forward and threw a punch with everything he had, aiming to smash the smug human into dust.

But once again, his massive, armor-plated fist went straight through Shinji's body like he wasn't even there.

"?!"

The beetle froze in confusion, staring at his own arm. This was the second time his blow had connected with nothing but air, and the phenomenon made no sense. Shinji hadn't dodged. He hadn't even blinked. Yet it felt like striking a ghost.

From the sidelines, Genos watched intently, his expression tense. He couldn't figure it out either. He'd seen tech-enhanced warriors and psychics with all kinds of strange powers, but this? This ability to let attacks pass through the body itself defied every law of physics he knew.

And then it clicked.

Back when Shinji had saved him from that earlier strike, he had touched Genos's shoulder right before the punch missed. Could it be... Shinji was moving so fast that he was slipping past the attacks entirely? So fast that both he and the enemy couldn't perceive the movement?

That would explain why it looked like the attack simply phased through him. It wasn't intangibility, it was movement beyond their comprehension. Genos was sure of it now. That brief touch earlier wasn't just to reassure him. Shinji had brought him along, pulled him out of danger with speed that bent the limits of time and perception.

His admiration shot through the roof. The difference between them wasn't just a gap in power. It was a whole different dimension.

He clenched his fists, watching every detail of his master's movements like a student memorizing a divine scripture. What he didn't realize, however, was that his entire theory was complete BS.

Shinji, unaware of the growing mythology Genos was building around him, remained focused. Saitama, standing off to the side, kept his usual blank expression. He wasn't impressed or concerned. If anything, he just looked mildly curious. He couldn't quite tell how Shinji was nullifying those attacks, but it wasn't enough to spark any serious interest.

Taking advantage of the brief pause, Shinji calmly stepped forward and tapped the beetle's side. It was just a light touch at the waist, no damage, no power behind it.

"...?"

Carnage Kabuto looked down, confused. "What the hell was that supposed to be? Are you stupid?"

He threw another punch, fast and brutal. There was no way he'd let it miss this time. But as soon as the punch started, Shinji disappeared.

In a blink, he reappeared on the far side of the arena.

Teleportation.

The beetle whirled around in shock. "So fast?"

He hadn't seen it at all. One moment, Shinji was right in front of him; the next, he was across the battlefield. Unbeknownst to the monster, Shinji had placed multiple Flying Thunder God marks across the arena in advance using his kunai, allowing him to jump freely from point to point.

Now standing at a distance, Shinji extended his right hand and began gathering chakra, some kind of look-alike energy. Energy swirled in his palm, spinning and compressing into a tight, glowing sphere.

Mental energy and physical energy twisted together, flowing in multiple directions and collapsing inward into a high-density spiral. The chakra began to roar quietly in his hand, forming a sphere that shimmered with raw, focused power.

It was the Rasengan.

Up until now, he hadn't used it in live combat. He had trained the shape and the control, but this would be the first time he tested it against a real opponent. And not just any opponent — a Dragon-level monster.

Monsters like Carnage Kabuto didn't come around often. They were too rare, too dangerous, and far too durable to waste on casual fighting. If Shinji was going to test a new jutsu, this was the perfect opportunity. Ordinary enemies would be obliterated before the technique could even stabilize.

Which made the beetle the perfect target.

He narrowed his eyes at the glowing sphere forming in Shinji's hand. He scoffed, voice full of contempt. "What? You think that tiny little ball is gonna stop me? Don't insult me."

But Genos felt something different. His mechanical sensors buzzed with unease as he observed the energy buildup. No ordinary technique gave off a signature like that.

No… I can feel it. That orb carries something incredibly dense and dangerous. Could Master Shinji really take down a monster like that with just this one attack?

He'd never seen the jutsu before, so he couldn't assess its full potential, but everything about it screamed lethal.

Shinji ignored the taunts completely. The Rasengan in his hand continued to spin, gaining speed, the energy tighter and more focused with every passing second. Once it reached full form, he started walking toward the enemy, calm as ever.

Carnage Kabuto actually relaxed slightly at the sight.

"Your dodging was impressive. I'll give you that. But if this is all your offense amounts to, then let me show you what real power looks like."

With a roar that shook the walls, he launched forward at breakneck speed, intending to finish it all with a single devastating punch. The ground cracked beneath his feet as he hurled his full weight forward.

But Shinji didn't blink.

Just as the punch was about to land—

He vanished.

"Huh?!"

Carnage Kabuto's eyes widened in disbelief. He twisted mid-attack, scanning the space ahead, but Shinji was gone.

What he didn't realize was that Shinji had already reappeared, standing inches from his chest.

And in Shinji's hand, the Rasengan had changed.

It no longer glowed with compressed chakra. It had turned black, a void-like sphere that twisted space itself around it.

Kamui + Rasengan.

Shinji didn't hesitate. He thrust the swirling black sphere directly into the beetle's gut.

There was no clang, no impact, no resistance.

His reinforced carapace, so tough it had once been declared indestructible, fractured instantly. The sphere sank in, dragging matter out of existence as it bored through flesh and bone. It passed straight through his body like it was made of paper.

"GRAAAHHH—!"

A tortured scream erupted from his mouth as blood exploded from the wound, gushing down in thick streams. He stumbled backward, legs faltering, eyes wide with pure panic.

He stared at the gaping hole in his abdomen, unable to comprehend what had just happened.

"What...?! I actually got hit?"

His voice trembled. The confidence from moments ago had vanished.

In the shadows, Dr. Genus looked on in horror. He had never seen Carnage Kabuto bleed, let alone collapse. He was the strongest creation Genus had ever built, and now he looked like a dying insect swatting at ghosts.

Genos also stood frozen, disbelief written all over his face.

That jutsu… it changed mid-fight?

He had sensed the overwhelming pressure of the original Rasengan. But the moment it struck the beetle, there was nothing. No energy burst, no shockwave.

It was like the orb had vanished on contact, yet the destruction it left behind was undeniable.

It was unnatural. Impossible! The moment the Rasengan struck, it didn't release an explosion — it erased matter. No shockwave, no heat, just... void.

It completely defied the laws of physics. If psychics could bend them, then Shinji had stepped outside those rules entirely.

Genos clenched his fists. His sensors had failed to catch even half of what happened. Despite watching with full focus, he hadn't seen the moment Shinji triggered that transformation or how the jutsu penetrated the beetle's armor like air.

Damn it...

He gritted his teeth in frustration. This was a once-in-a-lifetime chance to witness his master's true combat ability, and he couldn't even keep up with the basics. If this was Shinji's standard, then what business did a second-rate cyborg like him have claiming to be his student?

Maybe Master Shinji had been right to hesitate. Maybe he really wasn't strong enough to learn from someone operating on this level.

While Genos stood there, caught in his spiraling thoughts, Saitama simply watched with a neutral face. He was impressed, sure. Shinji's powers were flashy, complicated, and strong as hell. But something about all the spinning, teleporting, and glowing spheres felt a bit excessive to him. He couldn't help feeling a little disappointed. He wanted punches and kicks, not hard-to-understand abilities in the fight.

So this was the big Beetle-something? That was it?

Looked like he wouldn't get his turn after all.

"You... you bastard!" Carnage Kabuto howled, staggering, blood dripping from his abdomen in thick streams. "What the hell did you just do?! Where did you get power like that?!"

Shinji stood silently at first, his eyes dimming slightly as he looked at the wounded creature. Then he spoke, voice low.

"You really wanna know?"

The beetle blinked. He hadn't expected an answer. That was just a scream of rage, not a real question.

But now... he found himself frozen, watching. Somehow, Shinji's presence forced him to listen. Even with his body ripped open, he stood there, as if waiting for a revelation he didn't understand.

Even Genos leaned forward unconsciously, eyes gleaming.

Was this it? Was his master finally going to explain it all?Top of Form