Ah Cheng was the roommate of Lin Lie, and repeatedly tried cheering him up over the disappearance of Lie's father and brother.When Lie and Ji Shuangshuang needed to find a way to travel to Gansu, Lie decided to ask Cheng for help Cheng, as he had a driver's license. The two came across Cheng stealing a phone off a businessman with his mistress, leading to an altercation between him and Shuangshuang. Cheng witnessed Lie's Sword of Fu Xi move on its own causing Lie to spot Feng in the crowd but he disappeared when Cheng caught up with him.As Cheng drove them to Gansu, Lie and Shuangshuang told him of their ancestry to the Three Sovereigns Fu Xi and Nü-wa, respectively, and the release of Chiyou. Cheng assisted the two and the Nü-wa Clan when Chiyou's demon forces attacked the Clan's headquarters by running the demons over with his car