Way Down in the Hole
Cal sighed. "Look, I've been to a lot of places I shouldn't have been, and I've seen a lot of monsters put a lot of innocent people through a meat grinder in a lot of horrible ways. Some whip up clueless farmers with a cocktail of religion and lies and strap a bomb to their chest. Some pump kids full of drugs and stick assault rifles in their hands. You save the ones you can. The ones you can't - or that you need to kill to survive - well, you gotta do what you gotta do to keep going. If you want to blame someone for it, blame the people who put the grenades in their hands."
"That's not me giving you a pep talk. That's me telling what you need to do to stay alive. Because if you get wrapped up in guilt over the ones you couldn't save, it'll destroy you. I've seen it happen too many times. I don't know much about you guys, but from what I've seen you can take a shotgun to the face, but your hearts and minds are just as fragile as ours. And when one of you loses your grip... man, does it ever go bad. How many people are you gonna save, then? Or are they the ones that'll need saving?"
"Plenty of people are in a lot less danger than they were this morning. Most are gonna take a long time to recover, but that's not on you. You and yours scored a major victory today. Savour it. That's an order."