Rocket League tournament duplicates, what to do?

I recently pulled Nergal from my tournament rewards. The problem is that I already have Nergal and don't know if there's a use for the duplicate. Since Nergal is a black market item, I can't swap it up either. And trading with players is also not possible, as it is irreversible. Is there anything i can do with it? P.S: I'm on PS4 in case that makes a difference

Unfortunately, you can't do anything with it because you can't trade it!