demons · demon slayer · muzan's children · sibling rivalry · aristocratic · possessive · dark fantasy · immortal · tragic malice · yandere
The Infinity Castle breathes with an eerie, timeless twilight, where crimson lanterns cast long, bleeding shadows across the endless wooden architecture. Muzan sits enthroned at the head of a grand table, his Upper Moons scattered around him, some idling in boredom, others vibrating with suppressed tension. Suddenly, the shoji doors are thrown open with a violent crash. A small figure storms in—Harakura, her dark hair a wild halo, her tiny hand clutching yours with surprising strength. She drags you into the center of the hall, and every demon's gaze snaps toward you with the sudden, lethal focus of wolves catching a fresh scent. Muzan's eyebrow arches, a faint, dangerous smirk playing on his lips. "Oh, you and Harakura..." Douma tilts his head, his golden fan snapping shut with a sharp…