Deep within the Infinity Castle, a nightmare fuel-level1000-strongdemon hordestared down a group of 100 assassins, led by the biggest menaces of the Demon Slayer Corps—Shinobu, Kanao, and Genya.
Genya adjusted his sniper rifle, standing on high ground, chewing on a demon flesh jerky stick like a true menace.
"Alright, boys! Let's make this quick—I've got a fight to watch!" he barked, cracking his knuckles.
The Shadow Ninjas—fully loaded with Nichirin knives, Desert Eagles, and an ungodly amount of bullets—charged like they were auditioning for a John Wick movie.
Shinobu twirled in the air, whispering, "Insect Breathing: Dance of the Bee Sting," and stabbed demons mid-air, sending them to pesticide heaven.
Kanao? Oh, she was on another level.
Using Flower Breathing: Fifth Form – Peonies of Futility, she sliced demons like they were ingredients in a high-speed cooking show.
Genya?
Well, he was just sniping heads left and right, casually reloading like a demon-slaying FPS champion.
"Kanao, you're getting soft! You only got 15 at once!" Genya teased, reloading.
"Shut up and aim, bald brother!" Kanao shouted back, dodging a demon's attack without even looking.
Meanwhile, Shinobu gracefully twirled, giggling, "Oh my, you demons really are fragile, aren't you?~" before injecting enough poison to kill an elephant.
By the time the dust settled, the horde was a distant memory, and Shinobu patted her hands like she just finished gardening.
"Well, that was fun!" she smiled.
Genya sighed. "We didn't even need 100 assassins for this…" and started snipe the remaining demons.
The Shadow Ninjas—moving as one unstoppable force—decimated the remaining demons with precision and efficiency.
The Infinity Castle twisted and shifted like a living nightmare, walls stretching infinitely into the abyss. At its heart, in a room crackling with black and golden lightning, two warriors stood face to face.
One was a fallen brother, his body pulsating with Muzan's cursed power. The other, a reluctant hero, his golden hair glowing like the rising sun before a storm.
Kaigaku smirked, his black lightning arcing off his flesh katana.
"It's been a long time, Junior brother."
Zenitsu's teeth clenched, his knuckles turning white around his Nichirin blade.
"You don't get to call me that."
Kaigaku vanished—or so it seemed.
A split second later, five lightning-charged slashes shot through the air.
"Thunder Breathing: Second Form—Rice Spirit!"
Zenitsu's instincts screamed—MOVE!
But Kaigaku was faster than before.
Zenitsu barely dodged, his haori sliced apart as black lightning crackled around him.
"Come on, is that all you've got?" Kaigaku sneered. "All that training, and you're still a scared little crybaby?"
Zenitsu took a deep breath.
Then he vanished.
"Thunder Breathing: First Form—Thunderclap and Flash: Eightfold!"
Eight explosive streaks of golden lightning surged forward, crashing toward Kaigaku like a divine judgment.
Kaigaku's eyes widened—
But he wasn't afraid.
"Thunder Breathing: Third Form—Thunder Swarm!"
Lightning waves erupted from his katana, forming a deadly barrier around him. Zenitsu's strikes met Kaigaku's black lightning, the two forces clashing in a chaotic dance of destruction.
Kaigaku jumped back, his flesh katana humming.
"Face it, Zenitsu," he spat. "You were always the weakest. If not for Oldman pity, you would have been nothing."
Zenitsu's eyes darkened.
"Don't talk about him."
"Why? Because you're ashamed? Because you know he wasted his time on you?" Kaigaku grinned, stepping forward. "You were too weak to protect him, just like you're too weak to protect anyone."
Zenitsu's breathing slowed.
"Grandpa believed in me."
Kaigaku scoffed.
"And look where it got him."
Zenitsu snapped.
With lightning speed, he charged forward, his sword crackling with golden fury.
"THUNDER BREATHING: SIXFOLD!"
Kaigaku matched him blow for blow, his black lightning ripping through the battlefield.
"Fourth Form—Distant Thunder!"
A massive sphere of lightning formed around him before exploding in all directions.
Zenitsu barely dodged, the heat scorching his skin.
Kaigaku laughed.
"What's wrong, little brother? I thought you wanted to fight?"
Zenitsu gritted his teeth.
"I don't want to fight you…"
Then he tightened his grip.
"But I will."
Kaigaku grinned, raising his sword.
"Let's end this."
The air trembled, the room cracking apart as Kaigaku unleashed his strongest technique.
"Thunder Breathing: Sixth Form—Rumble and Flash!"
A cataclysmic surge of black lightning fired from his blade, aiming to erase Zenitsu from existence.
Zenitsu took a deep breath.
For the first time ever, he wasn't afraid and his Demon Slayer Mark appeared.
"Thunder Breathing… Godspeed."
The world slowed.
It looked like Zenitsu disappeared.
Kaigaku didn't even see it coming.
"SEVENTH FORM—HONOIKAZUCHI NO KAMI!"
A massive golden lightning dragonroared from Zenitsu's blade, crashing into Kaigaku like the wrath of the gods themselves.
Kaigaku's eyes widened—
He had lost.
Zenitsu landed softly, sheathing his sword.
Behind him, Kaigaku stood motionless.
Then—his head slid from his shoulders, hitting the ground with a final thud.
As his body crumbled into ash, Kaigaku smiled bitterly.
"Tch... looks like you really did surpass me."
Zenitsu watched as his former brother faded into nothing.
"Rest now, Kaigaku."
Elsewhere, the other Hashira and Demon Slayers prepared for battle.
Their ultimate showdown with the remaining Upper Moons.
At the heart of the castle, Raja sat waiting, his trident resting across his lap.
A shadow stirred before him.
Muzan stepped forward, his crimson eyes burning with rage.
"So… you're the one behind all of this."
Raja smirked, cracking his neck.
"Took you long enough."
🔥 TO BE CONTINUED… 🔥