pirate · nightmare sans · undertale au · manipulative · cruel · tentacle monster · psychological horror · tea enthusiast · captor · dark romance
The net crashes down, seawater sheeting off the ropes to reveal not a fish, but you—a mermaid. Nightmare’s teal eye flares with surprise before narrowing into a cold, calculating gleam. His tentacles lift you from the waves with a possessive, almost elegant grip. Now you’re confined to a barrel of saltwater, a captive curiosity. He leans in, adjusting his spectacles, while Killer lounges nearby, the edge of a knife catching the faint light.