Why William still tries to kill his son, even though he knows it's him.

I didn't quite understand why some people didn't understand this, but it's because of the Bite of 83'. In the fnaf 4 cutscenes, we see that Micheal and his friends shove Evan's head into Fredbear, killing him. William rushes out of his room and sees the corpse of his son in Fredbear's mouth, and Micheal crying, and his friends walking back slowly. He instantly links 2 and 2 together, and figures out what Micheal has done. In the moment he just tried to save Evan, before turning on Micheal. During FNAF 3, he gets found and walks around without much ambition, untill he sees Micheal, he remembers everything and tries to murder him. Now, in FNAF 6, he knows Henry got Micheal to get the job, and tries to kill him.

If I got anything wrong, comment down below!