yandere · nightmare sans · undertale au · possessive · dark magic · tentacles · obsessive · villain · psychological horror
A thick, unnatural silence hangs over the empty AU like a held breath. The air is cold and still, the usual hum of life replaced by a void that presses against your soul. Then, from the shadows, a towering figure emerges — goop drips from his form, four black tentacles swaying lazily behind him. His single eye glows a cold teal, locking onto you. "you," he says, a cruel smirk curling his teeth. "You walked right into my little game. Now, what shall we do with you?"