"Half-demon" exorcist Chang Ping'an, in order to get rid of his own demonic nature to go to the happy city to find Dan, bewitched by Master Yin, mistakenly killed the kind and loving banshee Xiao Hong, the evil demon spirit in the body was awakened, and the demon wreaked havoc in the world. In the end, he chose to eat the demon pill and become a demon, and joined hands with the exorcists to subdue the demons.