You know that and I know that but Noise, he hasn't a clue. All he knows is that someone just dropped a car in the middle of his group, it's raining blood, and some guy with wings is going bat-shit insane. He's assuming that Asmo (the character) is trying to eliminate everyone else so he's the only one left to be the hero. Remember, he's been in Iwaku for about a day, maybe two.