we always knew he was a psycho. from the very first chapter that has been very clear. the reason we support him is because he does society a favour and all his victims are monsters. by killing them he saves other people from becoming their next victims. his motives may not be commendable, as well as his methods (though fitting the criminal), but at the end of the day the world becomes a safer place thanks to his actions. And it's also logical that his past must show the beginning of his psycho obsession, which we see in his teenage years. the consequent accident shaped him into the person we see here, doing these "good deeds" not because he believes in revenge, or because of empathy etc., but bc of his own fcked up reasons. As long as his actions help people and harm monsters, he may go ahead and keep it up.
I read trace long time ago, I thought this was a different whole character. Man even if he kills bad people—he's still not far from them, he's more twisted than we think he is. Bro is a two faced