As already stated by others,I enjoyed the way you conveyed the brainwashed mindset, trivialising the bloodshed as "just another day at the office". However, I will echo the other comment here in saying the theme felt a little tagged on at the end. I don't like offering changes to others' works, but I do think with a few tweaks, you could have made it fit better. Otherwise, you convey the Battle Brothers narrative well, and I enjoyed reading it.