Tell him that you know he feels lonely inside and that he’s angry at the world, but that doesn’t mean he should just close himself off to it by throwing wine at everybody who tries to come close to him. There’s a lot of bad in the world, but there’s a lot of great things in the world, too, and there are
good people. People worth getting close to, to share life experiences and laughter with. He’s missing out on the good things the world has to offer by only focusing on the bad.
Y’know, some shounen protag bullshit like that