I'm going to delete my friends team on a game for stabbing me in the back
What did they do to piss you off so much?
They have made me angry in the past. I can't just forgive them for their mistakes.
Friends can make us angry but you shouldn't do something petty like deleting their team. It will make them angry and it won't solve anything.
I don't care if they are angry, I don't care if it doesn't fix anything, I want to make them feel some pain.
Talk to your friend. Seeking petty revenge doesn't solve the problem.