I'm familiar with the system, it's in the rulebook. It's his decisions on how to handle it by attacking another brand new player that I disliked, especially since that sort of thing was common for him and he seemed to get enjoyment from it. If you as a DM get enjoyment from killing your players then you're not the DM for me. I've played D&D off and on for 35 years, and those were the only two DMs I've played with that were actively trying to kill their players. Not my thing, which is why I don't play there anymore.