Screen 1 — Scene 1: The Surface Battle Begins
The Infinity Castle collapses into dust, and from its wreckage rises Muzan Kibutsuji — the original demon, the curse that began it all.
His veins glow red, his form monstrous yet regal, every heartbeat pulsing with corruption.
Around him stand the last warriors: Tanjiro and Venom, Rengoku, Giyu, Mitsuri, Obanai, Sanemi, and Gyomei.
The night trembles as the final confrontation begins.
> Muzan: "The night is eternal — and I am its god."
Tanjiro: "Then we'll bring the sun to you!"
Venom: "We kill gods too."
Rengoku: "Ready yourself, Muzan."
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Screen 2 — Round 1: Muzan's Storm
Muzan attacks first.
Tentacles explode from his back, slicing the ground faster than sound.
The Hashira scatter as debris and blood fly through the air.
Giyu deflects a strike with Water Breathing, Eleventh Form: Dead Calm.
Mitsuri cuts through two tendrils mid-air, her whip blade flashing pink.
Venom coats Tanjiro's body in molten-black armor, blocking the third whip and countering with a symbiotic punch that shakes the earth.
> Venom: "His blood burns like acid — avoid direct contact."
Tanjiro: "Then I'll burn hotter."
Rengoku and Sanemi flank from both sides — flame and wind clashing together in a roaring cyclone.
Gyomei smashes down with his flail, the ground cracking beneath the impact.
Result: Muzan unfazed but forced to reposition — his confidence begins to waver.
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Round 2 — The Venom Counterplan
Venom extends microscopic threads into the air, analyzing Muzan's biology.
He detects multiple cores — hearts and brains — moving independently within Muzan's body.
> Venom: "He's not one creature — he's seven. We hit all of them at once."
Giyu: "We'll synchronize through Tanjiro's breathing."
Venom connects to each Hashira through his symbiotic network, sharing Tanjiro's rhythm — every heartbeat in sync.
Coordinated Formation:
Gyomei anchors the center.
Rengoku and Sanemi rotate left and right.
Mitsuri and Obanai spiral in from above.
Giyu shields the others with water forms.
Tanjiro channels Sun Breathing: Thirteenth Form — Continuous Cycle.
They attack together — blades flashing like a constellation of sunlight and steel.
Muzan's regeneration falters for the first time in centuries.
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Round 3 — Venom's Heat Evolution
Muzan howls, his body splitting into hundreds of whip-tendrils.
He unleashes Blood Demon Art: Red Moon Flesh Storm — a rain of acidic blood.
The battlefield begins to melt.
Venom adapts, his armor glowing molten red as he absorbs the heat.
> Venom: "We'll burn the poison before it burns us."
Tanjiro: "Then let's make the sun rise early."
They merge power —
🔥 Sun Breathing x Symbiote Mode: Crimson Nova! 🔥
A spiral of black and orange energy erupts, cutting straight through Muzan's torso and vaporizing half his body.
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Round 4 — Muzan's Desperation
Muzan regenerates instantly but falters — Tamayo's poison still corrodes his blood.
He goes berserk, launching a storm of attacks faster than light.
Sanemi loses an arm; Mitsuri is struck through the chest but saved by Obanai's sacrifice.
> Obanai (bleeding): "You… you finish him, Mitsuri."
Mitsuri (crying): "No! Stay with me!"
Venom: "Focus. Grieve later. Kill him now."
Rengoku's mark flares white. He charges again, his blade blazing pure light.
Gyomei and Giyu follow — a hammering wall of strength and calm precision.
Tanjiro lands a strike through Muzan's chest, exposing his clustered hearts.
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Round 5 — The Final Dawn
The walls crumble.
Sunlight begins to pierce the night.
Muzan's skin smokes; he roars in defiance.
> Muzan: "I will not die — not to humans!"
Venom: "Then die to something older."
Venom fuses completely with Tanjiro, forming Solar Symbiote Form — glowing veins of molten gold running through black armor.
His blade shines like a newborn sun.
> Tanjiro: "Sun Breathing: Thirteenth Form — Final Cycle!"
Rengoku: "Flame Breathing: Ninth Form — Rengoku!"
Gyomei: "Stone Breathing: Volcanic Strike!"
Their attacks collide — a symphony of fire, sunlight, and stone.
Muzan's body implodes, vaporized before he can split apart.
The dawn consumes him.
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Screen 3 — After Muzan's Death
As the smoke clears, fragments of Muzan's cells cling to Tanjiro's wounds.
They slither inside his bloodstream.
In canon, this would birth the Demon King — but this time, Venom is waiting.
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Screen 4 — Venom's Resistance
Venom feels the intrusion first.
> Venom: "Something's crawling inside you. Not ours. We'll kill it."
Tanjiro (weak): "It's… Muzan… trying to take over."
Venom: "He picked the wrong body."
Venom expands through Tanjiro's veins, isolating and devouring the invading cells.
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Screen 5 — The Symbiote Learns
Venom doesn't just destroy Muzan — he learns from him.
He absorbs fragments of demonic DNA, gaining regenerative knowledge and strengthening his bond with Tanjiro.
> Venom: "He tried to consume you. We consumed him instead."
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Screen 6 — The Mental Battle
Inside Tanjiro's mind, Muzan's fading voice whispers:
> Muzan (echo): "You can't reject me… you carry my blood now."
Venom (growling): "Wrong. He carries me."
Tanjiro: "Get out of my head."
Venom manifests inside the bloodstream, purging every last fragment of demonic infection.
The corruption burns away like ash under sunlight.
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Screen 7 — Purified Power
Muzan's curse dissolves completely.
Tanjiro never becomes Demon King — instead, the power is purified.
He retains Muzan's sunlight immunity and rapid regeneration, but his humanity remains untouched.
His eyes glow red for a moment, then return to warm brown.
> Venom: "You almost became him."
Tanjiro: "No… I became stronger because I didn't."
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Screen 8 — Symbiotic Evolution: Solar Venom Mode
Venom evolves into his final form — Solar Venom Mode.
Effects:
Sunlight immunity retained.
Boosted stamina and reflexes.
No hunger or demonic corruption.
Perfect human-symbiote harmony.
> Rengoku (watching): "You burned the curse itself away."
Venom: "We don't share. We conquer."
Tanjiro (smiling): "Then we conquered evil together."
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Screen 9 — Epilogue: The Dawn
As the first true sunrise in a thousand years shines over the battlefield, the survivors collapse together — exhausted, alive, victorious.
> Rengoku (smiling faintly): "The sun… it's beautiful, isn't it?"
Venom (softly): "We burned the darkness. Together."
Tanjiro: "Everyone's still here… that's what matters."
The light washes over the ruins.
No demons remain.
The curse is gone.
Humanity breathes again.
Be continued — Final chapter