They can always spin their own justification for strange actions. I would avoid going into a lot of detail about the Thor love and thunder shirt in other words I will buy this narcissism. It can make you appear pretty if they have not experienced gaslighting or emotional manipulation themselves. It could undermine your authenticity with your friends. These are mutual friends so they like your ex too. They will be prepared to see the good in him and no doubt he has his own line on what happened. It will carefully reflect badly on you of course because he won’t be to blame for anything. Your best approach might be to rise above it. Simply state that you’ve moved past it and you wish him well for example.
Buy this shirt: Thor love and thunder shirt