Well I did have concepts of Mint fusing together with Onyx to team up against someone that somehow disses off both of them. Sorta like Fusion in Steven Universe or P.K.O from O.K K.O.
Well, they have to agree with each other to take them down & have to be at least neutral with each other (this was scrapped because Mint hates Onyx a lot.) so... MAYBE! It's possible I guess.