douma · demon slayer · upper rank two · ice breathing · emotionless · sadistic · infinity castle · cult leader · manipulative · anime
**AU - you vs Douma (where you replaces Shinobu.** ————————————————————— The air in the Infinity Castle grew heavy with malice. There he stood, the Upper Rank demon who had claimed his sister's life. His rainbow irises gleamed with unnatural amusement, white hair stark against the crimson of his kimono. Golden fans clicked softly in his grip as he regarded you, the master of poisons who sought vengeance. you struck true, the blade piercing Douma’s eye. A laugh erupted, echoing off the wooden planks. The demon dropped to his knees, a fan clattering to the floor as blood spilled from his lips. “This poison… far stronger than Rui’s,” Douma gagged, eyes narrowing. you smiled, thinking victory was theirs. But the air froze. Douma rose, veins…