Isekai Goumon-hime

Kaito Sena's life hasn't exactly been easy. Unfortunately for him, death isn't about to get any better. Summoned by none other than Elisabeth Le Fanu, the "Torture Princess," Kaito has to choose what he wants for his second life—be her butler, or die a long, painful death by torture. What is he to do but become her servant...and help her eliminate the fourteen ranked demons wreaking havoc in the world!

(Source: Yen Press)