Isekai Goumon-hime

After suffering a tragic death, Kaito Sena finds himself reborn into an unfamiliar world. His confusion is short-lived when a breathtakingly beautiful woman appears before him, introducing herself as the Torture Princess. Without hesitation, she commands him to swear absolute loyalty and serve her. Unsurprisingly, Kaito flatly refuses the absurd demand. In response, the enigmatic Elisabeth offers him a stark ultimatum: willingly become her personal butler, or endure agonizing torture until he perishes. Faced with such grim alternatives, Kaito quickly reconsiders his defiance and submits to her will. Bound to serve Elisabeth hand and foot, Kaito is thrust into her perilous mission. As the Torture Princess, she is tasked with hunting down and subjugating fourteen ranked demons alongside their human contractors. Yet, beneath the bloodshed and dark purpose lies a devastating secret. Once her grim duty is fulfilled, Elisabeth is condemned to a solitary death—destined to be utterly forsaken by heaven, earth, and all of creation. Now entangled in her fate, Kaito must navigate a treacherous path at the side of a doomed sovereign.