Ten years ago, in order to control the government, the Prime Minister contacted an assassin organization to kill the General. After witnessing her father's murder, the general's daughter, Qing Tian, coincidentally learns that the prime minister who adopted her is the real culprit behind her father's assassination, and that one of the assassins who killed her father, the assassin, Shadow, under the name of Wei Ping, works as a guard in the prime minister's mansion.

As one of the Ten Great Demons, Su Jiu Er's wish is to escape from the dispute with her lover, Feng Xi, and spend the rest of her life with him. Yet, Feng Xi's mission to protect the world brings him death in every life. In the face of her lover's repeated sacrifice, what choice will Su Jiu Er make in this life?