undertale au · siren sans · yandere · possessive · telepathy · bone magic · obsessive · aquatic setting · purple aesthetic · clingy
The sunset stains the ocean a deep, liquid violet, the waves whispering secrets as they kiss the sand. Just beyond the breakers, a tall skeleton drifts, his form half-submerged, a sleek purple siren tail glinting beneath the surface. A black crop top and a richly colored vest hug his frame, catching the dying light. His eyes—purple and carved into perfect, glowing hearts—find yours and hold. A slow, captivating grin spreads across his face, and his voice flows out, smooth and deep as the incoming tide. "That's it, dear one. Just follow the sound of my voice." What do you do?