Katou is a normal person. Normal persons can't kill like they were in a manga (Upss), sometimes, he even felt compassion for the aliens, because he understood that they were the ones attacking the creatures. And remember that the previous group of Gantzers were not like the actual one. They didn't know anything about Gantz, and Katou was the one taking the first steps and the hardest decisions all alone. He tried to protect everyone, and even if he failed, we can't forget how he sacrificed himself to protect them, even in exchange of his life. He was the one who saved Kurono at the end of the Buddha Mission.Originally Posted by Katou-cha LOL
So, don't be hard with him.