What is right and what justice?

The tour around the whole academy didn't take longer than an hour. It was already around noon, the thoughts of killing so many have repeated in my head thousands of times but with no result. Still felt nothing, like a stone that just observed a slaughter like that. I am not sure what I should think about it, is it an indicator of the insanity of a serial killer? I killed a few people before, but this is just completely different. This is over 100 people that lost their lives, 100 or so families that lost their beloved children, I don't even know how many elves I killed, how many demons I killed. I don't know any of these, and that's the worst thing, I didn't even manage to care enough about killing them to notice what race they were.