A new mission summoned them deep into the heart of Mount Natagumo, a place drowned in an eerie silence, shrouded in thick mist. Even the birds refused to sing. It was unnatural—oppressively so. The moment Tanjiro, Zenitsu, and Inosuke stepped onto the mountain path, an oppressive aura pressed down upon them like a suffocating weight.
Crows had warned of missing Demon Slayers. A team had been sent before… none had returned.
As they ventured in, they found tattered remains of Demon Slayer uniforms—still fresh, some stained with blood. But the warriors wearing them were still moving—puppets, bound and twisted by invisible threads, dancing with lifeless eyes.
Tanjiro sensed it.
The scent of fear. Of pain. Of control.
From the treetops, the enemy watched.
The Spider Demon Mother—her fingers danced above a webbed thread, controlling her victims like marionettes. She spoke no words, only smiled faintly, her eyes void of emotion.
Tanjiro's heart ached. "They're alive… they're still alive…" he muttered, dodging slashes and broken attacks from the puppet corpses. He moved swiftly, knocking them unconscious rather than killing them. His mercy enraged Inosuke, who wanted to tear through with brute strength, but Tanjiro remained calm—directing his movements like a flowing river.
And when the puppets could no longer be used… the demon broke their necks. Just like that. Discarded them.
Tanjiro's fury surged.
They found her in the forest clearing, alone, weaving her threads of death. Inosuke charged, but it was Tanjiro who closed the distance.
"Water Breathing, Fifth Form: Blessed Rain After the Drought."
A merciful strike.
A death without pain.
As her head rolled to the ground, the demon looked up to the sky and smiled. "So gentle… Thank you…" Her final thoughts drifted to Rui—the boy who called himself 'son.'
But the mountain wasn't safe yet.
The true terror revealed itself deeper in the forest.
Zenitsu had gone off on his own, chasing the sound of Nezuko's box. Instead, he found a nightmare. A pale child-like demon with spider features and a grotesque web of poison and thread. Zenitsu fought alone—his fear crippling him, venom already coursing through his veins.
But when he was unconscious—his body moved.
Calm. Precise.
"Thunder Breathing, First Form: Thunderclap and Flash – Sixfold."
A flurry of lightning-fast strikes illuminated the night as Zenitsu's sleeping strength unleashed pure devastation. But he collapsed, the poison burning in his blood.
Tanjiro and Inosuke, meanwhile, continued deeper.
They encountered a towering demon—a "Father" with monstrous strength and a body hardened like armor. Inosuke, for all his feral strength, was overwhelmed. His swords broke. He was flung like a ragdoll.
Tanjiro, bruised and breathing hard, took over. He leapt, twisting in the air, sensing the rhythm of the creature's movements. One wrong move would cost his life.
A final strike—clean, decisive—severed the beast's head.
The mountain went still… until a new scent chilled Tanjiro's blood.
The scent of pure malice.
He turned—just in time to see a pale boy in a white kimono descending the web like a god.
Rui.
"Are you here to steal my family?"
Tanjiro froze. Rui's eyes, like glass, stared into him—void of empathy, heavy with authority.
This was no ordinary demon.
The number engraved in Rui's eye gleamed faintly—
Lower Five of the Twelve Kizuki.
Tanjiro instinctively stepped back, Nezuko's box pressed to his chest.
The real battle had only just begun.