Obviously something bad is being done, but a mysterious line is being drawn at 'humans' It's sort of like 'I'm okay picking up a gun, and shooting my neighbors 5 pets, but not my neighbor. He doesn't want to kill humans, or humanoid things, yet strangely seems okay with it happening all around him. I'm not saying his views are wrong, or misguided based on my own beliefs. It's like walking into a warzone with earphones on and pretending that innocent people aren't getting killed around you. Just because he avoids that part, doesn't mean it doesn't happen, nor is it intended. Why is he okay with YOU killing them? He seems to want to play, but he knows that part of it is killing people. Lets ignore the obvious oddity of the situation. Also, notably, he will get credit for those kills in the quest, so while he didn't actually fire the shot, he still consents and is rewarded for their death. Notably, he could portal out for those fights or something, but you'll never get through Nightmare that way.

Those are the first two that I can think of.

Cultists page diablo 3