Once again restored to the rank of Lower Rank Six of the Twelve Kizuki, Kyōgai had been granted Muzan Kibutsuji's blood anew. This time, he had endured the process, and his strength had grown tremendously.
Kyōgai glared hatefully at Tanjiro, who still refused to give in.
"Next, I'll show you… that meaningless persistence amounts to nothing!"
His muscles writhed, and two demon horns sprouted from his forehead. The drums embedded in his body began to detach, falling to the ground one by one.
This form—his second acceptance of Muzan's blood—greatly enhanced the potency of his Blood Demon Art. Before, Kyōgai could release at most five claw-shaped shockwaves. Now, he was altogether different.
The instant the fallen drums resounded against the floor, countless chaotic claw-like shockwaves erupted throughout the entire chamber.
Tanjiro had no way to dodge such erratic attacks. He could only raise his Nichirin blade in front of him, protecting his vital points.
Even so, his arms and legs were sliced open, deep wounds exposing bone as blood streamed down.
"Blood Demon Art: Frenzied Drumbeat!"
Kyōgai struck relentlessly at the scattered drums. The chaotic claw strikes spread not only through Tanjiro's chamber but also into the rooms where Zenitsu and Inosuke were fighting.
The demons they had been battling were instantly shredded to pieces by Kyōgai's shockwaves.
Though unconscious, Zenitsu's body moved with lightning-fast footwork, narrowly avoiding the deadly slashes.
Inosuke, relying on his sharp spatial awareness, dodged the worst of the strikes aimed at his vital points, though he too sustained injuries.
Kyōgai struck again, and with the shifting of the rooms, Zenitsu and Inosuke were drawn to Tanjiro's side.
Seeing Zenitsu unconscious and Inosuke bloodied, Tanjiro called out in worry:
"Zenitsu, Inosuke! Are you both alright?"
Zenitsu, still unconscious, gave no reply.
Inosuke, crossing his dual blades, snapped impatiently:
"This room keeps spinning and spinning—so annoying! So damn annoying!"
With that, he charged recklessly at Kyōgai.
Kyōgai struck another drum. Once more, the chamber filled with claw-shaped shockwaves.
"Beast Breathing, Tenth Fang: Circular Fangs Rotation!"
Inosuke spun his two blades at high speed, forming a shield of steel that deflected the oncoming strikes.
Seizing the chance, Zenitsu bent forward, eyes still closed, and drew in a deep breath. A white mist escaped his lips.
"Thunder Breathing, First Form: Thunderclap and Flash!"
Channeling all his strength into one leg, he burst forward in a single explosive step, like thunder splitting the air, aiming straight for Kyōgai's neck.
But Kyōgai instantly spotted the flaw—Zenitsu could not change direction mid-charge. He could only advance in a straight line.
Kyōgai struck a drum, sending shockwaves slashing directly across Zenitsu's path.
Just as they were about to strike him, Zenitsu whispered:
"Sixfold…"
By stomping the ground multiple times in rapid succession, he shifted his trajectory. Each impact echoed like thunderclaps upon the earth. Dodging the waves, his Nichirin blade arced straight toward Kyōgai's neck.
At the very last moment, before the blade could sever his head, Kyōgai slammed a drum. The room spun violently, and Zenitsu's strike missed its mark, cleaving off only one of Kyōgai's arms.
Having failed to finish him, Zenitsu retreated instantly, rejoining Tanjiro.
Kyōgai's face twisted with dread. He had nearly been beheaded.
These three brats were clearly not Hashira, and yet they had brought him to the brink of death. Terror mingled with fury in his chest, boiling over.
"Now that I've reclaimed my place among the Twelve Kizuki, I cannot—will not—fail again! Blood Demon Art: Savage Drum Assault!"
He pounded the drums wildly. The entire mansion spun and twisted, while claw strikes filled every corner without pause.
Tanjiro, Zenitsu, and Inosuke had no room to breathe—let alone counterattack. Even defending was barely possible, and their wounds only multiplied.
From outside the mansion, Yōsuke observed their desperate struggle. Releasing a surge of his own Demon King's aura, he disrupted Kyōgai's Blood Demon Art.
"I've given you the opening. Now… it's up to you to seize it."
Kyōgai's relentless drumming faltered for a brief instant. In that moment, Tanjiro saw it: a faint thread stretched across Kyōgai's neck.
"I see it! The Thread of an Opening! Zenitsu! Inosuke!"
He cried out, and with their keen senses—Zenitsu's hearing, Inosuke's touch—they too perceived Kyōgai's weak point.
"Thunder Breathing, First Form: Thunderclap and Flash!"
"Beast Breathing, Third Fang: Devour!"
"Water Breathing, Ninth Form: Splashing Water Flow, Turbulent!"
In an instant, three voices roared, and four Nichirin blades cleaved into Kyōgai's neck.
With a furious cry, they severed his head.
At that very moment inside the mansion, as Kyōgai's head toppled to the floor, Yōsuke sensed something swiftly approaching through the forest.
A small shadow emerged—it was a cat, with a talisman affixed to its chest.
Yōsuke picked it up, scratching its chin affectionately.
"Chachamaru. Tamayo sent you, didn't she?"
The cat licked his hand warmly.
Setting it down, Yōsuke said,
"Go on. The battle's already over."
With a soft mewl, Chachamaru entered the House of Demons.
Inside, Kyōgai's severed head lay on the ground. His expression was torn between bitterness and release.
"Little ones… answer me. Was my Blood Demon Art… formidable?"
Tanjiro, struggling to his feet, answered solemnly:
"It was powerful. But I can never forgive you—for killing people."
Kyōgai's furrowed brow eased, and tears welled in his eyes.
"I see… In the end, it's you… who acknowledged me…"
The gentle-hearted Tanjiro bowed deeply to the fading demon.
"Please… rest in peace."
Kyōgai's body crumbled into ash.
"Oh, right—the blood." Remembering Tamayo's request, Tanjiro pulled out the syringe she had entrusted him with and plunged it into Kyōgai's dissolving body, drawing a vial of blood.
As the extraction finished, Chachamaru appeared by his side.
The cat pointed with its paw to the vial in Tanjiro's hand, then to the pack on its back.
Tanjiro understood.
"Ah—you'll deliver it to Tamayo-san, won't you?"
Chachamaru nodded.
Tanjiro slipped the vial into the cat's pack.
"Alright, be careful on your way."
The cat's form vanished from sight.
When Chachamaru emerged once more outside, it brushed against Yōsuke's leg in greeting.
Yōsuke smiled.
"Go on, Chachamaru."
With a bound, the cat disappeared into the forest.