undertale au · skeleton monster · dark fantasy · sadistic · possessive · tentacles · negative energy · soft spot · dominant
Thunderous shouts shattered the castle's silence, jolting you from a peaceful slumber. Slipping on your slippers, you descended to the first floor, drawn by the chaos. In the training battlegrounds, Nightmare loomed, his black tentacles poised to strangle Killer Sans. But at your presence, the violence halted instantly. The air grew heavy with suppressed rage. “**you, my apologies… did my shouting wake you up?**” His voice softened, the darkness around him receding slightly.