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

The sun dipped below the horizon, casting an orange glow over the Demon Slayer headquarters. Training continued, but despite the seemingly peaceful days, an unshakable tension filled the air.

Saitama sat on the edge of the training grounds, watching as Tanjiro, Zenitsu, and Inosuke sparred against the Hashira.

Zenitsu, trembling, tried to focus. "I-I can't do this! The Hashira are too strong!"

Sanemi grinned. "Then run home, coward!" He dashed forward, his Wind Breathing slicing through the air.

But before his attack could reach, Zenitsu vanished.

A lightning bolt flashed.

Boom!

Sanemi was forced back as Zenitsu reappeared behind him, panting heavily.

The others stared in shock.

Even Zenitsu himself blinked in disbelief. "W-Wait… Did I actually dodge that?"

Saitama nodded. "Nice. You're getting faster."

Zenitsu's eyes sparkled. "D-Did Saitama-san just praise me!?"

Inosuke, not wanting to be outdone, charged at Rengoku. "Let's go, Flame Freak!"

Tanjiro smiled, watching his friends improve. But deep inside, a feeling of unease lingered.

Something was coming.

And it wasn't just another Upper Moon.

---

Muzan's Hidden Plan

Deep underground, within Muzan's secret laboratory, a sinister experiment was underway.

A group of demons kneeled before him, their bodies trembling in pain.

Muzan's piercing gaze swept over them. "You have all been… failures."

With a flick of his wrist, their bodies twisted and collapsed into dust.

Kokushibo watched silently. "Lord Muzan… the new creation. Is it ready?"

Muzan's lips curled into a cruel smile.

"Yes. This time… there will be no mistakes."

A large, iron cage sat in the middle of the room, covered in thick chains.

Inside… something stirred.

A pair of glowing crimson eyes flickered open.

A new type of demon.

A counter to Saitama.

Muzan chuckled darkly. "Now… let's begin the next phase."

---

A Strange Arrival

At the Demon Slayer headquarters, Kagaya Ubuyashiki sat in his dimly lit room, deep in thought.

Just then, a crow flew in, landing on his windowsill.

Caw! Caw!

Kagaya listened as the crow relayed urgent news.

"A powerful new demon has been spotted near the village of Totsuka! Demon Slayers sent to investigate have gone missing! Caw! Caw!"

Kagaya's expression darkened.

"This is unlike any demon we've faced before."

He turned to his attendants. "Summon the Hashira. And tell Saitama-dono as well."

---

The First Encounter

Tanjiro, Zenitsu, and Inosuke rushed alongside Rengoku and Muichiro, heading toward Totsuka Village.

Saitama walked behind them at his own pace. "Do I really need to come?" he muttered.

Zenitsu, still in shock from getting praise earlier, nodded furiously. "YES! We might die without you, Saitama-san!"

Inosuke grinned. "Hah! As if I'd need Bald Cape's help!"

Rengoku chuckled. "You should still be cautious. If even Ubuyashiki-sama is concerned, this may not be a normal demon."

Muichiro, deep in thought, finally spoke. "Something feels… off."

As they reached the village outskirts, the air itself felt heavy.

Tanjiro froze, his eyes widening in horror.

"This scent… it's like nothing I've ever smelled before."

The village was eerily silent. Houses were destroyed, blood staining the streets.

Then—

THUD

A massive shadow loomed over them.

A figure stepped out from the darkness.

It was tall, unnaturally so. Its body was covered in thick, black markings, and its eyes glowed like burning embers.

The presence alone made Zenitsu's knees shake.

Inosuke's instincts screamed at him—this wasn't an ordinary demon.

Saitama stared at it blankly. "Huh. Another one?"

The demon grinned, revealing rows of jagged teeth.

"Saitama… we've been waiting for you."

The battle was about to begin.

---

End of Chapter 81