[Brunbb]

He kills to prevent innocent people from being hurt. He is not simply a mindless killer. You could argue that innocent people get hurt during the fighting between super heroes and villains, as this story did, but you also have to take into account how many people they save. But, even if you made that excuse, in the beginning the X-Men and Avengers are fighting the Brood (I think it was them). Frank never does anything about them. He gets rid of all the heroes on Earth and leaves it open for an invasion from any outside force. That's much worse.