The story takes place in the twilight years of the Six Yao Realm. The protagonist Zan is now over seventy years old. He was originally a charlatan on the verge of death. He accidentally saved a dying demon cultivator and was entrusted with the "Soul-Eating Poison Technique" and half of the "Six Yao Selfless Sutra" by him before his death. In order to seek a chance for survival, he embarked on the path of cultivating immortality, but due to the characteristics of the skill, he became an "emotional devourer" - he could absorb the joy, anger, sorrow and joy of others to improve his cultivation, but he himself was like a frozen lake, unable to produce real emotions anymore. In the process of practicing, he got acquainted with the "Xuanwu", a spiritual beast that carries Luo Shu and can determine the location of heaven and earth, and became involved in the unprecedented dispute between the "Equality Society" and the Immortal Cultivation Sect. Facing the leader of the "Equality Society" - the idealist who pursues absolute fairness and wants to abolish all privileges of cultivating immortals, and the revenge of the reincarnation of his close relatives who were forced to sacrifice to save the common people, Zan Mo is struggling in the whirlpool of cause and effect. He gradually discovered that his path of cultivation was closely related to the loosening of the ancient "Five Elements Return to Ruins Seal" and the turbulence of the origin of the Six Yao Realm. In the end, he needs to make a choice between "using emotions as food to achieve Hunyuan" and "cutting off cause and effect to regain people's hearts", and find his own "true source of Yi Dao" between the inevitability of history and personal free will.
