Chapter 30 30: The Rage That Awakens the Demon Slayer Mark - From Thunder Breathing to the Multiverse - NovelsTime

From Thunder Breathing to the Multiverse

Chapter 30 30: The Rage That Awakens the Demon Slayer Mark

Author: FaaanzKun
updatedAt: 2025-09-01

Tachibana Kyūjō gently touched his chin, nodding in quiet satisfaction.

He was still processing the power behind the flying slash he had just unleashed.

Using a Nichirin Blade to launch a long-range attack came with both strengths and weaknesses when compared to using one's fists.

The main advantage was the blade itself—slim, razor-sharp, and able to concentrate energy into a single edge. When done right, its destructive force could surpass even a direct punch.

But unlike fists, the sword wasn't part of the body.

Controlling it to release a flying slash required precision, timing, and total mastery. It was far more complex than Akaza's Formless Style, which let him throw punches like bullets with no wind-up.

That's why Kyūjō's slash, for all its power, still had a slight delay—just enough of a gap to become a fatal weakness in the hands of a true master.

Someone like… Kokushibō, who now stood not far away.

And for demons, there was only one real way to kill them—decapitation by Nichirin Blade. Energy blasts and projectiles were meaningless if they couldn't slice the neck clean.

Kokushibō had witnessed countless techniques far beyond the realm of common sense. But even so, this one... made him pause.

Not because of its raw power—he'd seen stronger.

But because of Kyūjō's sheer ability to learn.

It was unnatural. Illogical.

He too had mastered the Transparent World.

He had lived for centuries, seen endless combat.

Yet even he could never copy a technique after watching it just once…

Let alone execute it on the first try.

Rage began to simmer deep within Kokushibō's chest.

He respected Kyūjō's resolve as a swordsman.

But he despised the terrifying possibility that this human… might one day surpass him.

In Kyūjō's form, he saw the shadow of a man he could never forget.

Yoriichi.

His younger brother.

The one person he could never defeat, no matter how many lifetimes passed.

Their difference in strength now was still vast… but talent like that, cursed as it was, just needed time. Given a few more years, Kyūjō could very well reach that same realm.

If Muzan himself came down right now and offered to turn Kyūjō into a demon, Kokushibō would still refuse.

This swordsman… had to die.

Tonight.

And anyone who dared get in his way—he would cut them down without hesitation.

— — —

After Yoriichi's death, Kokushibō's resolve to never lose again had twisted into a maddening obsession.

To uphold it, he'd thrown away everything.

His honor as a samurai.

His humanity.

His name.

His family.

Even love.

He had sacrificed everything just to stay ahead.

— — —

Meanwhile, Kyūjō could feel Kokushibō's killing intent burning behind him.

It was like standing at the mouth of a volcano—moments before it erupted.

His brow twitched slightly.

But he quickly forced his nerves to calm.

No time to think. Only act.

He glanced at Akaza, whose body was slowly regenerating.

He had to end this—now, before things spiraled even further.

Kyūjō took a deep breath.

His blade slid back into its sheath—but not in the traditional way.

This time, his right hand flipped the hilt in reverse, like he was holding a dagger.

"Huff... hah..."

Gold-tinged breath poured from his lungs, spiraling down to his legs.

Blue and yellow lightning surged across his skin.

And then—he vanished.

— — —

"Thunder Breathing, Fifth Form: Heat Lightning – Modified!"

"Thunder Breathing, First Form: Thunderclap and Flash!"

Two techniques fused into one.

A draw slash at impossible speed.

Even before the blade fully cleared the sheath, it had already turned red-hot—glowing like molten steel, cloaked in roaring thunder.

It flew straight toward Akaza's neck, slicing through his spine like a blade through butter.

Only then did Akaza's awareness catch up to reality.

He felt the searing heat at his neck—and his body, demon as it was, didn't even have time to react.

"No…!"

"I haven't reached the pinnacle yet—!"

"I can't die here! I need to become stronger!! Stronger than this!!!"

That desperate scream—laced with fury and obsession—sparked something inside him.

An evolution.

His demon body trembled, preparing to transform—his power stretching toward an unknown limit.

But before that change could happen—

A massive surge of killing intent crashed into the battlefield.

A second blade.

Blood-red. Covered in countless open, blinking eyes.

It slammed into Kyūjō's strike from the side.

So close…

Just a hair's breadth away…

Kyūjō had nearly severed Akaza's neck entirely.

Akaza had nearly completed his transformation.

But Kokushibō, without hesitation or shame, had chosen to intervene.

— — —

Kyūjō let out a sharp breath. He had known this might happen.

Even before he swung, he had calculated that Kokushibō wouldn't let him finish Akaza off.

Their relationship might not have been friendly…

But even so, demons protected their own when it mattered.

Kyūjō had to try.

If he succeeded, he might still have a chance—however slim—against Kokushibō alone.

But if Akaza survived… fighting both of them was suicide.

Even if Akaza pretended to value fair duels, Kyūjō had no illusions.

He never trusted the honor of a demon.

— — —

Kokushibō's blade bore down with overwhelming pressure, and Kyūjō's balance began to slip.

He clenched the hilt with both hands and braced himself.

At the point where their blades collided—one blazing with crimson fire, the other writhing with blinking demonic eyes—neither man spoke.

Heat radiated from Kyūjō's blade like a furnace.

Even Akaza, still halfway conscious, flinched at the sheer temperature, his eyeballs rolling back from the searing pain.

Kokushibō glanced at Kyūjō's blade with a glimmer of admiration.

"Your sword… for a mere human… is truly exceptional."

Despite the fact that Kyūjō's Nichirin Blade had pierced into Kokushibō's own, the Upper Rank One demon slowly began to push him back.

Bit by bit, Kyūjō's blade was nudged away from Akaza's neck…

Until finally—it slipped free.

Kyūjō exhaled.

With a twist of his body, he kicked off and flipped backward—creating distance once more.

His eyes locked on Kokushibō.

Now filled with something he rarely showed.

Anger.

"…Why are you pushing me this far?"

"Why can't we just… live in peace?!"

His voice cracked, thick with emotion.

Kyūjō's breath hitched—and then his rage surged.

It overflowed, unstoppable.

His eyes burned like wildfire.

"Fine… then let's see how you handle this!"

"Demon Slayer Mark—ACTIVATE!!"

— — —

His heartbeat exploded.

It pounded like war drums from within his chest—loud enough to echo in the ears of everyone nearby.

Steam erupted from his pores. His entire body began to burn.

He inhaled—long and deep.

"Huff... hah…"

And with all his strength, Kyūjō drew in the air, igniting the Thunder Breathing that had become part of him.

Lightning surged through his lungs—then raced through his veins, his muscles, and up into his face.

Then—

Glowing marks, shaped like jagged bolts of lightning, bloomed across his forehead and eyes like a shining net.

— — —

Kyūjō could feel it.

The surge. The aura.

He probably looked insanely cool right now.

But for some reason… it brought him no joy.

Yeah, it looked cool.

But the cost?

His lifespan.

Years. Dozens of them—gone.

Kyūjō had never wanted to awaken the Demon Slayer Mark. Wasn't it nice to live a long life?

In his previous life, he only made it to twenty-seven.

Now again… was he doomed to die young?

But without this Mark, he had zero chance of defeating Kokushibō.

He was still just human.

One clean hit—and he was done for.

If he had to activate it eventually…

Then it was better to do it now, while he could still fight.

Not wait until he collapsed—too broken to even lift his sword.

— — —

His eyes lit up like torches in the darkness.

Bolts of lightning sparked across his pupils—like a moving painting. A storm trapped inside.

Kokushibō watched the transformation…

Then laughed.

"Fufufu… hahaha… Hahahahaha!"

"I can feel it—your fury. It's radiating off you."

"So… you already know, don't you? That those who awaken the Demon Slayer Mark don't live past twenty-five."

"In that case… you understand me, don't you?"

"Knowing that fate… wouldn't you rather become a demon?"

Kyūjō raised his sword.

He was done listening.

His brows furrowed. His voice rose in a furious yell as he lunged forward—

"I'M YOUR DAD!!"

"TAKE YOUR DAMN LOGIC AND DIE WITH IT!!"

— — —

Demon Slayer Mark + Transparent World + Crimson Blade + Protagonist Buff + Main Character Aura…

Can Kyūjō actually win this?!

This moment marks the turning point.

From here on…

Kyūjō's life will never be the same.

— — — — — — — — — — — — — — — —

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