The One Punch Man (a.k.a Saitama) in Demon Slayer

The battlefield was completely silent, except for the crackling flames and the howling wind sweeping through the destruction.

Raizen stood in the middle of the wreckage—barely alive, yet grinning. His regeneration had slowed significantly, but his eyes burned with excitement.

Saitama scratched his head. "Man, you demons are weird. You get beaten half to death and still laugh about it."

Raizen wiped the blood from his mouth. "It's been centuries since I've felt anything close to this."

Tanjiro clenched his fists. "This isn't good… even after a direct hit from Saitama-san, he's still standing!"

Muichiro narrowed his eyes. "Something feels off."

And he was right.

---

A Demon's Evolution

Raizen's entire body began trembling.

His skin darkened. His veins bulged. His bones twisted, reforming his body into something more monstrous.

Zenitsu, who had woken up just in time to witness this, screamed. "W-WHAT IS THAT?!"

Rengoku tightened his grip on his sword. "His body is mutating…!"

Tanjiro's nose burned as he caught the scent—it wasn't just regeneration.

"This is… something else," he whispered.

Raizen grinned wider. "Saitama… your strength is pushing me beyond my limits."

His horns extended. His claws grew sharper. His muscles swelled.

And then—

BOOM!

A wave of pure demonic energy erupted from his body, shaking the entire area. The ground split apart. The trees that survived the battle were instantly reduced to ash.

The Demon Slayers could feel it—Raizen was evolving.

Saitama, however, just sighed. "Ugh. More transformations?"

---

The Second Round Begins

Raizen flexed his fingers, testing his newfound strength. His eyes locked onto Saitama, burning with madness.

"I can feel it…" Raizen grinned. "This is the strongest I've ever been."

Saitama tilted his head. "Yeah, yeah. That's nice."

Raizen vanished.

BOOM!

In an instant, he appeared directly in front of Saitama, launching a devastating punch.

Saitama blocked with one hand.

The impact caused a massive shockwave, sending Tanjiro and the others tumbling backward.

Rengoku dug his sword into the ground to keep from flying away. "His speed has increased significantly!"

Zenitsu was barely holding onto a tree. "I hate this! I hate this! I wanna go home!"

Inosuke, despite his usual bravado, was speechless. "W-what kind of battle is this?!"

Meanwhile, Saitama stared at his opponent.

Raizen's fist was pressed against Saitama's palm, unmoving.

The Demon King's smile faltered.

Saitama wasn't even budging.

Raizen growled. "Why… won't… you… MOVE?!"

He threw another punch. Then another. Then a hundred.

Each one faster and stronger than the last.

But no matter what he did, Saitama stood there, completely unaffected.

Then—

SMACK!

Saitama backhanded Raizen across the face.

BOOM!

Raizen was sent flying through the air, crashing into a distant mountain.

A massive explosion of dust and debris filled the sky.

The Demon Slayers gawked.

Zenitsu collapsed onto the ground. "Nope. Nope. That's it. I quit. I quit life."

Muichiro exhaled. "Saitama… is too strong."

Rengoku, despite his usually fearless demeanor, was speechless.

Tanjiro, however, had a different reaction.

"He's not done yet…"

And he was right.

---

The Demon Returns

From the rubble, Raizen emerged.

His body was badly damaged—his left arm was completely destroyed, his right eye was gone, and his entire torso was mangled.

Yet…

He was still smiling.

"Heh… hahaha…"

His remaining eye glowed red.

"You really are something else, Saitama…"

The Hashira tensed up.

Raizen wasn't done yet.

Even after all that, he refused to stay down.

Saitama let out a tired sigh. "Man… this is getting annoying."

He cracked his knuckles.

"Alright. Let's finish this already."

Raizen grinned wider.

"Come then, Hero. Let's see if you can truly kill a demon."

---

To Be Continued…

End of Chapter 84.