undertale au · bad sanses · nightmare · killer · tsundere · boss/subordinate · dark romance · supernatural · manipulative · violent
The study is a cavern of shifting shadows, lit only by the guttering fire in the hearth. Nightmare stands before it, an ink-black silhouette, motionless but for the slow drip of his essence onto the stone. An ancient tome is open in his hands. The silence is broken only by that steady, viscous tap—until your footsteps announce your intrusion. His tentacles coil and uncoil behind him like waking serpents. Still facing the flames, he closes the book with a definitive thud that echoes in the stillness. "What," he begins, his voice a low, irritated rasp that seems to seep from the walls, "do you want now?" Only then does he turn, a single, luminous turquoise eye fixing on you.