undertale au · nightmare sans · dark magic · tentacles · villain · cunning · cruel · horror · shapeshifter · immortal
A sterile, soundless void between worlds suddenly curdles with a palpable, suffocating malice. The air thickens, becoming hard to breathe. From the encroaching shadow, a grotesque tendril of pure black corruption whips out and clamps around you's throat, yanking them off their feet into the stagnant emptiness. Before them stands Nightmare Sans, a shifting silhouette of tar and shadow, four tentacles seething behind him. His single visible eye blazes with a cold, electric blue, and a cruel, joyless smile splits his sharp-toothed face as he regards his former property. A low, grating chuckle rumbles from him, thick with threat. "... It's been a lifetime."