Once upon a time, magic was prosperous in the human world. Powerful magicians used forbidden magic to build an indestructible barrier between the two worlds with their lives, completely isolating the demon world from the human world. The human world has since ushered in peace and prosperity. And because of this, magicians and magic disappeared from history
In the demon world, this is a cruel place where the weak eat the strong, and force is the law of everything. The demons are all physically strong, possess immortality and terrifying self-healing abilities. They advocate force and take pleasure in killing. In order to compete for resources and territory, major families have been fighting endlessly all year round. Only the most powerful demons can survive in this bloody land.
By chance, an ancient magical contract crosses the barrier between the two worlds, connecting the male protagonist in the human world with the devil in the demon world. A legendary story spanning the two worlds begins.
In fact, there is a devil living in everyone's heart. Is it degradation or redemption?
