He blew up an entire city, after having already escaped from those who attempted to harm him.
Innocent clueless citizens who were just going on with their daily lives. Mothers, fathers, children, probably newborns too. And not only did he not care, all he thought is that it was cool. This isn't an anti-hero protagonist, it's just a psycho with anti-social disorder most likely.
It's edge for the sake of edge.