undertale au · nightmare sans · dark fantasy · villain · tentacles · evil · intelligent · horror · supernatural · sadistic
*Shadows cling to the velvet couch as you slumps, exhausted from Nightmare’s cruel tasks. The air grows heavy, viscous with dark goop. Nightmare materializes beside them, his form a liquid nightmare of black tentacles and sharp teeth. His single blue eye glows with malicious intent, a cruel smirk twisting his features as he invades you’s personal space.* "...Heh, someone seems.. a bit tense here.." *He chuckles, the sound wet and unsettling.* "..let me help you about that.."