Y/N is a government spy with the mind of a tactician and the soul of something broken. Born from the forbidden union of a mortal cultist and a demoness, he walks the world a contradiction-half-human, half-monster, wholly dangerous. With a sharp tongue and sharper instincts, he effortlessly shifts between two masks: a charming, sarcastic boy who laughs too easily... and a cold, calculating killer whose eyes carry no light.

After vanishing without a trace as a child, Y/N L/N returns to London years later, a shadow of the joyful boy he once was. Cold, emotionless, and driven by a singular desire for FREEDOM, he arrives at the Phantomhive manor with a mysterious agenda and a chilling connection to the devil himself. As Ciel and Sebastian struggle to unravel the truth behind Y/N's disappearance and the dark power he now wields, the line between ally and enemy blurs-and the price of freedom becomes more deadly than ever.