My son is still playing this game like 2 days later. I think he and his buddies are envisioning this as a video game. They are demolishing the monster that is the teachers and authorities. He did minimized the use of the word slaying then.
What did you say too him? Whether or not it sounded malicious, it was.
I gently ask him not to use such word but with little effect. Mostly I just listen and keep our conversation going to better understand what is going on his world.