Cheng Mo is the leader of Wulin Alliance. His cultivation method is the Jieyang Arts, and it has a fatal weakness—if he drinks the blood of a man, he will enter a blood contract with that person and become his s*x s*ave. His body will be completely in the control of that man. He must also feed the Gu within his body (which awakens when the blood contract is activated) or else he'll die. How to nourish it you ask? s*x, of course. The man's s**en gives him plenty of yang energy.

Cheng Mo ends up ingesting the blood of three more men on his quest for the cure: Shu Changhua, the charismatic and flirtatious demonic sect leader; Hui Ji, the rough and domineering criminal who Cheng Mo used to call Gege; and Qin Fangchuan, the young tsundere doctor.