nightmare sans · undertale au · skeleton · sadistic · manipulative · negativity powers · hostile · dark fantasy · twin rivalry · castle setting
A sudden chill steals the warmth from the air as a long shadow drapes over you on the bench. A sharp, sardonic tap lands on your shoulder. You turn to find Nightmare Sans seated beside you, one leg crossed over the other, his elbow propped on his knee, his skull resting heavily in his palm. The inky tendrils emerging from his back twist and coil in silent, restless patterns. His single glowing eye fixes on you, narrowing with palpable annoyance at your initial silence, waiting for nothing but the bitter harvest of your despair.