Suggested by Sonic Sinister is definitely a tough fighter but he won’t be able to defeat Gambit here. Gambit has gotten many different powerups over the years which have made him a true powerhouse. When he’s not holding back the guy can even go up against cosmic threats. While Sinister usually starts off at a higher base than Gambit, his peak is considerably lower which puts him at a big disadvantage in this fight. Gambit wins.