Zhang Xiaofan is a simple, kindhearted boy from Grasstemple Village whose life is shattered when his entire community is massacred overnight. As one of the few survivors, he is taken in by the prestigious Qingyun Sect, the leaders of the righteous path. However, Xiaofan struggles with poor talent and a secret burden: a dark, Buddhist-Daoist hybrid cultivation technique and a sinister demonic artifact known as the Sinister Bead.

The story follows his journey as he matures in the shadow of his talented friend Lin Jingyu. His life takes a tragic turn during an expedition where he falls in love with Bi Yao, the daughter of the Ghost King (leader of the demonic sect). When the "Righteous Path" attempts to execute Xiaofan for his forbidden knowledge, Bi Yao sacrifices her soul to save him, leaving him in a state of despair. In Season 2, Xiaofan abandons his identity to become the cold-blooded assassin Gui Li, serving the demonic sect in a desperate, decade-long quest to resurrect his lost love, while his former senior Lu Xueqi watches from the distance, torn between her duty and her feelings for him.