The battlefield shifted.
The moment Dōma's icy domain shattered into nothingness, a ripple coursed through the demons. Their Lord's throne was bleeding, their mightiest pillars falling one by one. The Demon Slayer Corps, battered and bloodied, felt it too—like a breath of fire in their lungs.
"We… we can win," whispered a young slayer, gripping his blade tighter. Across the warfront, battle cries rose louder. Hope, sharp and dangerous, had returned.
On another front, a storm of moonlit blades carved through reality itself. Kokushibo's Moon Breathing unleashed crescents that bent like serpents, each swing a constellation of death.
Murata stood at the center of it—no longer the ordinary swordsman once overlooked. His breath glowed, galaxies spinning in his eyes. With each swing of his blade, starlight erupted, fragments of infinite skies colliding with Kokushibo's lunar fury.
Galaxy Breathing, Third Form: Supernova Scatter!The explosion of radiance tore through the slashes, scattering them like dust across a night sky. Kokushibo's single eye narrowed. "This… breathing. This is no trivial invention."
Tanjiro rushed beside Murata, Hinokami Kagura blazing from his blade. "We'll take him together!" His aura flared, fiery arcs mixing with Murata's starlit glow.
For the first time, Kokushibo felt pressured—his strikes finding resistance in a union he did not foresee. His words came low, almost reverent:"Two stars daring to outshine the moon… pitiful, yet… intriguing."
Elsewhere, fire clashed with the eternal strength of the Upper Moon. Rengoku's sword burned hotter with each breath, his body tearing itself apart but his spirit unyielding.
"Akaza!" he roared, flame-wreathed blade cutting through the night. "This ends now!"
Akaza's fists, each strike like thunder, hammered back with relentless force. His voice dripped with fury and desperation. "You again… why won't you die like the rest?!"
Their clash was no longer just power—it was destiny. Sparks and flame lit the air as sword and fist collided again and again. Akaza's regeneration struggled against the ceaseless inferno, his form beginning to falter.
And in that fleeting heartbeat of weakness, Rengoku's spirit ignited beyond flesh.Flame Breathing, Ninth Form: Rengoku.
A blazing dragon consumed the battlefield, swallowing Akaza whole. The demon screamed, his body burning, his form disintegrating in the tide of flame. Yet even as he vanished, his voice carried a last curse:
"…Why… why couldn't I reach…?"
When the fire faded, only Rengoku stood, chest heaving, blade still burning in his hand.
All around, slayers rallied. Seeing Rengoku victorious, seeing Zenitsu, Inosuke, and Shinobu fell Dōma, seeing Murata awaken beyond all limits—these were sparks that lit a forest fire in their hearts.
The demons still outnumbered them, but fear now lurked behind their red eyes. The Corps had found its rhythm, its hope.
At the heart of the war, Muzan's wrath pulsed stronger than ever. His blood boiled, his power lashing at Tharion in waves that could shatter mountains. The Demon King roared, his throne shaking under the weight of defiance.
But now, for the first time in centuries, Muzan faced a battlefield where the humans no longer fought in despair.They fought in fire, thunder, poison, and starlight.
The tide had turned.
The battlefield trembled under their clash.
Kokushibo's blade moved like an endless tide of death—crescent slashes folding over themselves, spiraling outward, slicing the very air into ribbons. His Moon Breathing was overwhelming, a dance of distorted arcs that left no opening.
But this time, he was not facing one opponent.
Tanjiro's flames burned with relentless fury, his Hinokami Kagura igniting the dark with each step. The sun's fire lit the arena, fierce and unyielding, cutting paths through Kokushibo's crescents.
Beside him, Murata radiated with starlight. Galaxy Breathing spun like the cosmos itself, each form vast, radiant, and unbound. His blade traced arcs that split open Kokushibo's waves, scattering them like meteors shattering upon a shield of light.
Together—fire and stars—they fought as one.
"Galaxy Breathing, Fourth Form: Spiral Nebula!"Murata twisted his blade in a spiraling surge, starlit arcs whirling like a galaxy collapsing inward. The force bent Kokushibo's slashes off-course, scattering their momentum.
Tanjiro surged in, his body screaming in pain but his spirit blazing higher.Hinokami Kagura, Twelfth Form: Flame Dance!Twin fiery arcs tore through the fractured moon blades, striking toward Kokushibo's chest.
The Upper Moon met them with sheer ferocity."Moon Breathing, Sixteenth Form: Lunar Benediction!"His sword unleashed a storm of blades, a celestial hurricane that clashed against flame and star. Sparks blinded the battlefield, the sound like a thousand storms colliding.
Tanjiro's arms trembled under the pressure. Every strike rattled his bones, his lungs burning, yet his will pressed him forward.Murata, too, felt his soul shatter under the weight of Kokushibo's killing intent. His Galaxy Breathing devoured stamina like a bottomless abyss.
Yet something greater held them aloft.The image of everyone fighting, everyone bleeding for this war. Zenitsu's thunder echoing in the distance. Inosuke's beastly roars beside Shinobu's sharp poison strikes. Rengoku's flames still burning, blazing bright even after victory.
They were not fighting alone.
Kokushibo's lone eye glowed like a void, his voice low and cutting."Two sparks daring to rise against the Moon… You are insects dancing in starlight. And yet…" His grip tightened, his aura swelling into a monstrous tide. "…why do you shine so brightly?"
He swung.The sky split.The floor crumbled beneath the weight of his technique.
But this time, the sparks did not falter.
Tanjiro's flames intertwined with Murata's stars, weaving together into an impossible brilliance. Fire roared across the starlit arcs, blazing constellations igniting around them. For a heartbeat, the battlefield was no longer darkness, but a burning night sky.
Together, they roared—"Hinokami Kagura!""Galaxy Breathing!"
Their blades struck in unison.
And for the first time, Kokushibo staggered.
The clash shook the very foundations of the Infinity Castle.
Kokushibo staggered backward, his blade arm trembling from the sheer force of Murata and Tanjiro's united strike. His body was riddled with burns from the sun flames, his chest slashed open by the galaxy arcs that shone like collapsing stars.
For the first time since his ascension into demonhood, Kokushibo bled—not regeneration, not instant recovery, but a wound that clung stubbornly to him.
His many eyes quivered, one twitching toward Tanjiro's blazing figure, another toward Murata's radiant starlight.Yoriichi… and something else… a breathing I have never seen, yet feels older than time itself.
Kokushibo snarled, rage consuming his once-proud composure."Do not think you can eclipse me! I am the Moon itself, eternal!"
He surged forward with his most devastating strike yet—"Moon Breathing, Eighteenth Form: Moon-Dragon's Eclipse!"His blade unleashed a monstrous dragon-shaped crescent, its body spiraling outward like a tidal wave of blades, seeking to engulf them both.
Murata's eyes narrowed, every nerve in his body alight."Galaxy Breathing, Seventh Form: Starfall Descent!"He leapt, his sword tracing constellations across the void, each starburst exploding against the dragon's body, shredding it apart.
Tanjiro followed with his own desperate surge, lungs burning as he screamed—"Hinokami Kagura: Flame-Wheel!"His fiery arc tore down the collapsing remnants, driving straight into Kokushibo's chest.
The impact was cataclysmic.
Kokushibo's body convulsed as flames and starlight devoured him. His eyes widened, a thousand regrets flashing within them. He saw his brother's face—Yoriichi's quiet smile, the brilliance of the Sun that he could never touch.
And then, his body split apart. His head tumbled, seared by Tanjiro's flames, shattered by Murata's celestial strike.
Upper Moon One—Kokushibo—had fallen.
The Infinity Castle screamed. The walls convulsed, floors folding and twisting as if in agony. The very air became unstable, cracks spiderwebbing through the endless corridors.
Far away, a duel raged with apocalyptic fury.
Tharion stood against Muzan, his limiter shattered, his body radiating with a dome of fire so hot it warped the space around him. Every strike was a blaze of judgment, forcing Muzan back inch by inch.
Muzan snarled, his body endlessly regenerating, tendrils whipping and snapping at Tharion like storms of flesh. But the fire dome consumed everything it touched, each attack reduced to ash before it could close in.
The two forces—demon king and outsider warrior—clashed with such violence that every slayer, every demon, felt it.
Amid this chaos, one lone slayer stumbled into a narrow corridor. His breaths were ragged, his sword slick with demon blood.
And then he froze.
There, seated in eerie serenity, was Nakime, her pale fingers plucking her biwa with calm precision. Every note twisted the castle, reshaping reality, obeying Muzan's will. Her eyes—empty, yet sharp—flickered toward him, and the next chord she played sent the floor splitting beneath his feet.
The slayer tightened his grip on his sword. He had found the source—the beating heart of the castle.
For the first time, the Infinity Castle itself was vulnerable.
The stage was set.The Moon had fallen.The Castle was trembling.And at its burning heart—Muzan and Tharion's duel was reaching its breaking point.
The final battle had begun.