Hong Kong Movie: Be a Policeman at the Beginning

Jiajun travels back in time to a movie and TV show where he conquers demons. He carries with him the most powerful system for slaying demons, subduing demons and supporting justice, and becomes a rich boy of 18 or 19. He and Ma Ji were classmates before, but they never played together. I don't know if this is a world of police and robbers from Hong Kong movies, or a world that is a fusion of Hong Kong movies and ghost movies? I heard that the police station has super policeman Chen Jiaju, a slightly crazy exorcist policeman, and the gang boss Liangkun~~ "Ding, the host has been detected, and the most powerful demon-killing, subduing, and justice system is being integrated..." "Ding, the most powerful demon-killing, subduing, and justice system has been successfully integrated, and the newbies will be rewarded with a gift package," "Ding, congratulations to the host for getting the Marrow Cleansing Pill x1," "Ding~~" This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.