It's worth mentioning that just because Mister Sinister will be the villain in the future-set Wolverine 3 doesn't mean that he will exclusively be the antagonist of that film. Thanks to those aforementioned insane experiments, he has what can best be described as complete control over every cell in his body - which on a certain level makes him immortal. As a result, it's possible that we could wind up seeing him, played by the same actor, in X-Men movies from a variety of different decades -- including the 90s set X-Men sequel, the stalled Gambit solo movie, or even Deadpool 2. In fact, his presence could ultimately help to define and the upcoming slate of titles from the franchise, now that the series has completed the trilogy that started with First Class and ended with Apocalypse.