The trial had ended, but the atmosphere in the Demon Slayer Corps Headquarters hadn't eased. The presence of the silent, blood-drenched giant in thorned armor and wolf-hide cape lingered like a specter of death.
The name Doom Slayer echoed in the minds of all those who had witnessed the clash.
Word of his sheer power had already begun to ripple through the Corps like a storm. A foreign warrior—one who made Upper Moons look like child's play. Hashiras had returned to their posts in wary silence, conversations hushed behind closed doors. Even Sanemi, his pride wounded more than his throat, had not spoken since the encounter.
But something more terrifying brewed.
Far away, within one of Muzan's hidden domains—somewhere between reality and nightmare—Upper Moon Five, Gyokko, emerged from his cursed porcelain vase, slithering through dimensions with grotesque elegance.
"My, my…" he croaked, a dozen blinking eyes across his warped body twitching in excitement. "What… is this… scent of death… so thick… so unrefined yet intoxicating."
He slithered closer to one of his vases, a grotesque scrying device that pulsed with demonic energy.
Within it, a vision played: a figure—giant, armored in hellish metal, bathed in demon blood—standing unmoved in a sea of corpses. Doom Slayer.
Gyokko cackled like broken pottery, voice bouncing with delight. "A new canvas! Oh, Muzan-sama will be pleased! Let me offer this one a masterpiece! A gallery of blood and bones!"
Without warning, Gyokko vanished into his vase, teleporting through the demon realm and materializing… in the mortal world.
Somewhere in the Eastern Mountain Range
The night was windless. Still.
The Slayer stood atop a cliff, scanning the forest below. He had not returned to the Corps HQ, instead opting to roam alone—stalking demons that dared to emerge. His armor still bore the viscera of uncountable kills. His Shield Saw buzzed faintly on his left arm, waiting.
He wasn't hunting.
He was waiting.
Then the ground pulsed. Once. Twice. Cracks ruptured the earth ahead like spiderwebs. A giant porcelain vase burst through, ceramic chunks spraying in every direction.
And there stood Gyokko. His serpentine, twisted body slithered from the debris, grinning from ear to ear.
"Good evening, outsider," Gyokko cooed. "You're quite the noisy killer. You're not from around here, are you? But… that armor, that violence… it's art! Brutal, primitive… but art!"
The Slayer didn't move. Not even a breath. His green visor glinted in the moonlight. A soft wind passed, brushing his wolf-hide cape.
Gyokko tilted his head. "No words? No scream? Not even a whisper of fear?"
The Slayer took one step forward.
Then another.
Gyokko sneered. "Very well! Let me make you SCREAM THEN!"
Vases erupted around the area, summoning grotesque, fleshy, fish-like demons with writhing limbs and skulls for mouths. They charged at the Slayer.
He moved.
Shotgun out. Boom. A demon's head exploded.
He charged through them like a tank, Shield Saw roaring, slicing through fish-spawn like paper.
Blood painted the forest. Gyokko's laughter faded into confusion.
"W-What? They're… they're supposed to regenerate! You didn't even use a Nichirin Blade!"
The Slayer stomped toward the largest vase. His Power Gauntlet pulsed, and with a BANG, he shattered it with one punch.
Gyokko blinked across to another vase, appearing behind the Slayer now. "You think you're the first killer I've seen? You're just flesh and—"
The Slayer turned. Fast. With a sudden burst of Accelerator energy, he blitzed across the distance, grabbed Gyokko mid-sentence, and slammed him into the ground hard enough to leave a crater.
Gyokko's body twisted, limbs flailing. "This... this isn't art! This is savagery! Brutality! No respect for form!"
As Gyokko tried to teleport again, the Slayer hurled his Impaler, the chained spike-tipped spear, pinning Gyokko mid-warp. The vase cracked. Gyokko screamed.
"Y-You can't KILL me like this! My head! My HEAD must be—"
The Slayer grabbed his Chainshot, fired it into the vase, and ripped it apart with a brutal pull.
He grabbed Gyokko, holding him up by the throat, squeezing, as if inspecting what kind of mockery this demon was.
And then, the cold voice again.
"You are not art."
He revved the Shield Saw and carved Gyokko into two, diagonally, in a rain of blood, guts, and shards of demonic flesh. His screams faded into the night.
There was no need for Nichirin.
There was only Slayer.
Back at the Corps Headquarters
The crow relaying intel returned in a panic. The Hashiras assembled. Oyakata-sama sat still, listening.
Mitsuri's face was pale. "The report says… Upper Rank 5 is… dead?"
"How?" Giyu's voice was calm but sharp.
"The crow says the body… or what remained of it… wasn't even a head. It was just… paste," one of the Kakushi whispered.
Iguro stared at the floor. "Even the Upper Moons don't die like that… What kind of being is he?"
Oyakata-sama's face held a faint, almost imperceptible smile. "He is not from our world. But perhaps… the gods of another realm sent him to help."