Help looking for a title I forgot

I need some help to look for a manhua where the MC is a mushroom. He uses someone's identity to turn himself into a human. The world they live got monster crisis that you'll be affected if a monster wounded you. The ML is high position guard officials that is feared due to his cold heartedness when he randomly kills people who try to enter the safety zone area of uninfected people. In fact, ML is very great at spotting who is infected. Which was revealed when MC "new random colleague" was shot by ML but MC remember that someone in the group was wounded and the other groups before they got there wasn't infected, that's when he realized the kind "new random colleague" has been infected but keep silent.