My Sister Stole My Fiancé, So I Married the Sea Demon King

"Back from the apocalypse, I returned to the ritual where humans sacrifice girls to monsters. My scheming sister got reborn too. She stole the ""gentle"" Night Demon—my torturer in our past life—and shoved me toward the brutal Sea Fiend. She never knew the Night Demon’s body brings 24 hours of burning agony. But I wielded a psychic-sound curse. On the wedding night, I killed the Sea Fiend, and made it bow. Now I rule the abyss, laughing as she screams in hell’s lava. This life, I’ll start from the wasteland—and take revenge on the “gods” who treated us like lab rats."