How can I win this confrontation?

Your confrontation is pointless, you can't win with a narcissistic person. He would never comprehend what you could possibly say to him, it would just be a waste of your time. In his mind he is right and the world is all wrong, he doesn't have a problem, you do. In his mind he is justified in being a bully in haring others, he doesn't comprehend what he does is wrong. In his mind he is incapable of taking responsibility for his actions and behaviors. He probably doesn't even comprehend who you are. Bullies are hurting over some issue in their lives and they take it out on whoever is standing in front of them that day. He probably has no idea how much he is hurting you, he can't comprehend it. You wouldn't make things more difficult for him, he wouldn't even comprehend what you say.