After My Rebirth, I Contracted a Demon King to Be My Servant.

A wealthy lady with a deep hatred, in order to find out her enemies and let them get their due retribution, when she was dying, she sold her soul to the devil and was reborn. This demon is none other than Mo Zun, the supreme ruler of the demon world. The reason why the two can form a master-servant relationship is due to their previous lives. In their previous life, the two were an enviable couple of gods and immortals. Because they violated the rules of heaven, one soul was scattered and the other fell into the devil's path. After two lifetimes of entanglement, the lovers finally got married.