It turns out that Jon Hamm was set to appear in a post-credits scene as Mister Sinister, a villain folks have been waiting to see in the X-Men movie universe for years now. However, due to the production being completely overhauled, his scene has been removed.
On the bright side, The Tracking Board’s revealed that another well-liked star is joining The New Mutants instead. While Hamm’s Mister Sinister is out, Antonio Banderas is now in. He’ll likewise cameo as a villain in the film’s tag sequence, though despite how that appears, TB maintains that he’s not simply taking over the role of Sinister and is playing a different, unspecified antagonist.