In ancient times, the human emperor, Zhao Ming, made a request on behalf of the people and sacrificed himself to resist the Divine Realm. After Zhao Ming fell, his beloved Hun Dunzhu risked his life to save a part of his soul, establishing the cycle of reincarnation forever. In the distant future, Zhao Ming was reincarnated as Xie Xuechen, the leader of the Immortal Alliance, while Hun Dunzhu became the Holy Maiden Mu Xuanling in the Dark Domain. The two were eventually reunited in the human world, but they forgot their pasts, becoming rivals in the battle of “Justice vs. Evil.” Mu Xuanling saved the seriously injured Xie Xuechen in the Dark Domain and forced him to travel together in gratitude for saving her life.