I know it's that simple. If I thought he could improve for the better, I would have had the talk with him. But he has put forth zero indication that he wants to change (drastically cut down on gaming, go to bed earlier, not slam every door when he stumbles back home drunk, etc.).

I've subtly expressed that I don't like some of what he does and he immediately shoots it down. He claims watching hours upon hours of anime is fine because he's 'nerdy now' and he wants to embrace that niche. I've told him I don't like that he comes back blacked out all the time and gets pizza crumbs all over the living room couch. He just does not want to change.

This is my situation for the next 3 months. I'd rather end college with a neutral living relationship than a hostile one. It's just a lesson for me to either pull off living on my own in the future financially or if I can't do that than to vet very very hard next time.