I'm going to ruin a chance of a promotion for a coworker
What makes you want to ruin your coworker's promotion?
He criticized me about something after I worked my butt off helping him recently.
Taking on other people's problems can throw you off balance, at the expense of your own well being. Work on what you have rather than focusing on what someone else is getting.
I'm going to tell my manager how we are friends but that he shouldn't be getting promoted because I'm concerned about him.
If you want to say anything to your manager, limit it to how much you enjoyed helping your coworker. Going all negative will reflect poorly on you and ultimately backfire.