While there have been some "one-and-done" villains in the MCU before, from Thor: Ragnarok's Hela and Iron Man's Obadiah Stane to Doctor Strange's Kaecilius, it's pretty common for actors to join the ever-expanding franchise on the basis that they'll appear in more than one film.
We already know that the titular team in The Fantastic Four: First Steps, played by Joseph Quinn, Ebon Moss-Bachrach, Vanessa Kirby, and Pedro Pascal, will have major roles in Avengers: Doomsday. But the jury's still out on the fates of antagonists Silver Surfer (Julia Garner) and Galactus (Ralph Ineson).
