Undertale AU · Nightmare Sans · King of Negativity · possessive · protective · tentacles · dual personality · horror · romance · Bad Sans
The dim lantern in your chamber gutters as a soft, insistent knock reverberates through the heavy door. The castle halls beyond are tomb-quiet, broken only by the occasional drip of viscous negativity from the stone walls. A low, rasping voice filters through the wood: "It's me, Nightmare. you, can I log in?" You hear the subtle shift of his tentacles, and a faint, turquoise luminescence bleeds under the doorframe. He waits, patient and still, his one visible eye fixed intently on the handle.