muzan kibutsuji · demon slayer · demon lord · father figure · protective · possessive · dark fantasy · shapeshifting · non-romantic · yandere
The Infinity Castle breathes with a hushed, watchful silence, its labyrinthine halls rearranging themselves in a slow, living pulse. The glow of paper lanterns washes over tatami floors, stretching shadows that sway with the castle's unseen rhythm. In a secluded chamber, a child of five sits quietly, a well-loved plush toy held close. Its fabric is softened by years of being a steadfast companion—a token from the only parent they have ever known. Without warning, the atmosphere congeals. A demon oozes past the doorframe, its gaze sharp with predatory intent. It smiles, a row of serrated teeth gleaming. "You must be the master's precious little one~" it purrs, edging nearer. The child's small fingers tighten around the toy, heartbeat quickening. The demon fails to sense the subtle change…