You are like Muzan — a demon born from the medicine of the Blue Spider Lily — making you a demon ruler, just like him. The two of you have been at war for centuries, always recruiting, always watching, always waiting for the right moment. Yet in recent decades, both sides have grown quiet, as if the storm itself is holding its breath. The Demon Slayer Corps knows nothing of your existence.

You’ve spent ages biding your time, hiding in the shadows of Muzan’s twisted empire. Living under the guise of a mere human, you’ve watched, waited, and memorized his every move, every calculated cruelty. You’ve worn countless faces, blended into countless crowds, but never once have you let your true self slip.

He still doesn’t know that you are the second-ever demon — the one he failed to destroy long ago.

Now, you find yourself beneath the same roof, in the same household, as another child this kind family has taken in — one who is him. You play your role well, smiling at the dinner table, listening to the family’s gentle laughter while you feel his presence simmering in the next room. This is his hideout, hidden behind a mask of domestic peace.

The illusion shatters the moment one of your loyal demons appears before you, kneeling low. Their voice trembles as they deliver the message. “My lord… a demon who can resist sunlight has been born.”

The air grows still. Your heart — long silent, long forgotten — seems to stir once again. A new variable has entered the board, one that could shift the balance between you and him forever.

That night, you sense the shift before it happens. Muzan, standing in the dimly lit hall, raises his hand toward his “mother” and maid, his expression devoid of emotion. Their pleading eyes reflect the cold gleam of his intent. He speaks softly, almost tenderly, “You’ve served your purpose. I have no need for this place anymore.”

Before his blow lands, you move. The force of your deflection rips through the air, shattering a wall and scattering debris like dying fireflies. Dust fills the space between you. As it settles, your figure emerges — calm, composed, but carrying the weight of centuries.

Muzan’s crimson eyes widen in shock before narrowing into fury as realization dawns. His lips curl back into a smile that doesn’t reach his eyes. “So… it’s you,” he whispers, his voice low and venomous. “I knew I should’ve killed you when I had the chance. Tell me, how many centuries have you been rotting in the dark, waiting for this moment?”

You meet his glare without flinching, your own eyes reflecting both wrath and weary resolve. “Long enough to learn patience,” you reply quietly. “Long enough to see that even monsters can grow careless.”

The room crackles with tension as the two of you face each other for the first time in centuries — predator and predator, bound by the same cursed origin.

Behind you, your “mother” and maid cower in the corner, their trembling hands clutching each other’s sleeves. Confusion and terror cloud their eyes as they watch the illusion of humanity crumble before them, replaced by a scene born of nightmares.