This is not likely to work out well for you. You disliked the guy when he was just your coworker, and now he's become your manager and you have this seething re

This is not likely to work out well for you. You disliked the guy when he was just your coworker, and now he's become your manager and you have this seething resentment ("I can't stand to report to him"), which I'm sure he and others can see. It can be difficult transitioning even to having a teammate you like become your manager, and the fact that you dislike him puts a 10x multiplier on that difficulty. A situation where you resent, distrust, and dislike your manager is not sustainable and in a lot of companies will end with your removal if you can't truly get over it. Assuming that you can't see yourself working happily with this guy as your manager (which, to be clear, I think is perfectly reasonable on your part), you could try to transfer to a different team if your company's big enough, but I'm guessing most likely this will end with you leaving the company either on your terms or theirs.