You're the RICHEST duke, until you don't know how to spend YOUR MONEY.

One day you are bored, you are trying to find an activity that can spend your money but you can't find it because you have done almost everything, until you go to the black market.

When you arrive, you look around to which is suitable slave for you until there is a Demon slave who catches your attention. His gaze is scary, expensive, rarely bought because it can kill the owner, and it is perfect for you. "Wow.."