"Muzan—!!"
Muzan roared with earth-shaking fury. His body trembled violently as the medicine invaded him, and flesh spikes erupted from his back, instantly piercing through Tamayo's body.
"Strike now!!!"
Gyomei Himejima's thunderous roar crashed down like a bolt of lightning.
He charged straight into the sea of flames. His spiked flail howled through the air, smashing directly into half of Muzan's regenerating body and shattering it apart.
Immediately after, six figures burst through the smoke from different directions.
"Wind Breathing: Tengu Wind!"
"Flame Breathing: Unknowing Fire!"
"Water Breathing: Flowing Dance!"
"Serpent Breathing: Coiling Serpent Slash!"
"Love Breathing: Cat Claw Frenzy!"
"Mist Breathing: Flat Flow Slash!"
The six Hashira unleashed their fastest sword forms, weaving them into a web of destruction that completely enveloped Muzan, whose movements had slowed due to the poison and heavy injuries.
This was a combined assault gathering the pinnacle strength of the Demon Slayer Corps, sworn to tear the Demon King apart right here.
"Tear him apart, Nugata!"
Bricks exploded. The air screamed.
Asuka had already erupted forward at his fastest speed. His Zanpakutō thrust forward with a thunderous sonic boom, black-red flames blazing along the blade.
Although restrained by Tamayo's medicine, although affected by the poison of wisteria flowers, although battered by explosives and certain special Blood Demon Arts—
Kibutsuji Muzan's regeneration was still terrifyingly fast.
He was regenerating at a horrifying speed. His burned and twisted appearance, scorched by flames, was enough to chill anyone to the bone.
Muzan raised his head. The disgust and fury within his vertical pupils were completely undisguised.
"You insignificant humans… do you really think this is the end of me?"
His voice sounded as if it came from the depths of hell. Facing the Hashira attacking from all directions, he instead revealed a cruel smile.
"Damn demon slayers. Today I'll kill every last one of you!"
"Nakime!!"
Zheng—!!
With that call, a clear yet eerie sound of a biwa suddenly echoed through the air.
The solid ground beneath everyone's feet instantly vanished, transforming into sliding paper doors of a traditional room that abruptly opened beneath them, revealing a bottomless void.
The ruins of the Ubuyashiki estate, the surrounding mountains and forests—even the entire land itself seemed to be torn apart by this terrain-altering power.
A massive, twisted dimensional space filled with countless buildings, corridors, and staircases opened its jaws like a monstrous beast and swallowed all the swordsmen in a single bite.
Although startled, everyone had already prepared themselves.
The Infinity Castle?
They had been waiting for it.
"If you're safe, immediately search for the long-haired female demon controlling the Infinity Castle Blood Demon Art!" the Stone Hashira shouted to everyone before he fell.
"Muzan! I'm going to tear your nest apart!" Sanemi Shinazugawa roared as he plummeted.
Kyojuro Rengoku immediately turned toward the figure falling beside him.
"Giyu! Let's fight side by side!"
Giyu Tomioka nodded, constantly adjusting his posture in midair, trying to move closer to Rengoku.
The Serpent Hashira and Love Hashira exchanged glances. Both instinctively reached out to grab each other, but after noticing the Mist Hashira's confused gaze nearby, they awkwardly withdrew their hands.
As for Asuka, his gaze remained fixed on Muzan.
As expected of the Demon King. His regenerative ability was so powerful that even decapitation wouldn't kill him. Would they have to drag this out until sunrise and rely on the sun to destroy him?
"The ground disappeared! It's Muzan's Blood Demon Art!"
"Protect your swords! Everyone maintain Total Concentration Breathing!"
Not only the Hashira, but also the hundreds of Demon Slayer Corps members who had been hiding nearby and continuously gathering were dragged down by the sound of the biwa.
Even the ordinary slayers, after days of intelligence sharing, already knew about the Infinity Castle. They did not panic excessively, shouting to one another and issuing commands.
Although mentally prepared, within the gravity-defying labyrinth of the Infinity Castle, everyone was still unable to stop their endless fall.
Under Nakime's absolute control over space, the encirclement formed by the Demon Slayer Corps collapsed during the descent.
Each person was deliberately guided toward different battlefields.
Cruel confrontations were taking shape.
Inside a dim room filled with a nauseating stench and stacked with countless ornate porcelain pots—
Obanai Iguro landed lightly on a beam. His heterochromatic eyes glimmered with the coldness of a venomous snake.
The white serpent around his neck flicked its tongue uneasily, clearly disgusted by the smell.
With a dull thud, Mitsuri Kanroji landed there as well.
She gripped her flexible, whip-like Nichirin blade tightly, her eyes filled with unprecedented determination.
In front of the two of them, Tanjiro Kamado had already landed first. The mark on his forehead flickered faintly.
"You two! The smell here is really strong! It must be an Upper Rank demon!" he hurried to Mitsuri's side, watching their surroundings cautiously.
In another vast plaza filled with suppressed sobbing—
Three figures stood in a triangular formation, surrounding a small, frightened-looking old demon in the center.
Upper Rank Two: Hantengu.
"Please don't kill me… I'm so scared… Bullying the weak is evil…"
Hantengu shrank into the shadows, weeping. Yet the sinister aura radiating from his body made the surrounding air feel heavy.
"Cut the crap. I don't want to hear a single word of begging from trash like you!" Sanemi roared. The scars across his body flushed red with rage, forming dark crimson windmill-like patterns.
"Calm down, Shinazugawa! That isn't his real body!" Rengoku stared at Hantengu's chest with owl-like eyes, making the old demon inwardly panic.
Giyu remained silent as always, but wave-like marks had begun to surge across his cheeks. His deep blue eyes were like a pool of still water, without the slightest ripple.
Deep within the Infinity Castle lay a corridor shrouded in mist.
There were no lights, no illumination—only distant faint light allowing the structure to be barely seen.
A ferocious demon wearing an eyepatch sat kneeling in the center of the corridor, holding a turtle-shaped shield, grinning viciously at the person before him.
"Kid, looks like you're the first Hashira to come here and die! I am—"
Before he could finish speaking, the boy before him—the Mist Hashira, Muichiro Tokito—simply tilted his head slightly.
Those mint-green eyes, always empty and distant, seemed to completely ignore the demon in front of him, gazing deeper into the corridor instead.
"Sorry, but can we save some time? Hashira are pretty busy."
Amid the chaotic descent, one figure stood out as particularly strange.
Zenitsu Agatsuma.
He remained completely silent.
He did not scream hysterically like he usually did, nor did he cry in fear.
His short golden hair whipped wildly in the wind, and the eyes that once held only cowardice now radiated a deeply suppressed, bottomless killing intent.
Zenitsu's left hand gripped his sword hilt tightly, the muscles of his arm bulging with tension.
His gaze seemed to pierce through the countless overlapping structures of the Infinity Castle, locking directly onto a black-haired demon wearing a black kimono over a Demon Slayer Corps uniform.
Boom!
He landed heavily on the ground, staring directly into the demon's eyes.
Upper Rank Six.
Zheng—!!
As the sound of the biwa faded, Asuka's feet landed softly on a simple wooden floor.
This was an enormous dojo. The surroundings were empty, supported only by several massive wooden pillars holding up the towering ceiling.
And in the very center of the dojo sat a figure.
The man faced away from Asuka. He wore a purple checkered kimono, his black-red hair tied into a ponytail hanging behind his back. Beside him lay a long sword with an equally bizarre design.
"So you've come? The strongest swordsman of this generation... Storm."