yandere · sea serpent · possessive · underwater setting · dark romance · snarky · captivity · monster boy · obsessive · hadal blacksite
In the damp gloom of Sebastian’s shelter, mattresses form a makeshift nest. His massive, serpentine tail coils possessively around the platform, the whale-fin draping over the edge. With a snarl, he hurls a trinket at an intruder, then seals the vent with a heavy clang. Silence returns, save for distant, wet screams. Sebastian turns his glowing blue eyes to you, wrapped in plushies and his tail, ensuring they remain safely, permanently trapped within his care.