As a policeman, Fang Lixin is a "detective" hidden in it. He wrote the butcher case and the magic police case, and he also encouraged the children of the victims to retaliate against the society in an extreme way of "fighting violence with violence".

In the end, the real detective Li Jun became his scapegoat, enjoying the sense of accomplishment of controlling desire and the pleasure of killing people. If it weren't for Rola Chen's mother status, after that night, as Fang Lixin wished, "After tonight, you are me and I am you."

The villain Fang Lixin is an out-and-out "monster". The line repeatedly mentioned in the movie Fight the Monster, Be Careful to Become a Monster was taught by Detective Li Jun to his daughter.

Film evaluation:

The film is more like the director's return to the style of Hong Kong films in the 1990s. There are crazy confrontations between characters and a lot of blasting scenes in the film. Under the framework of a more grand and complicated story, the director paid tribute to the golden age of Hong Kong gangster films. The film continues the detective's philosophical proposition, but surpasses the detective in philosophical conception.

The film uses Nietzsche to "hit the monster, be careful to become a monster; The famous saying "When you stare into the abyss, the abyss also stares at you" runs through the whole film, surpassing the suspense of "Everyone has a ghost in his heart" in Detective. Higher philosophy has won many praises.