10 Marvel Cinematic Universe Villains Who Need To Make A Comeback

9. Ultron

Appeared In: Avengers: Age of Ultron. Ultron left a pretty big mark on the MCU when he appeared in last year's Avengers sequel, thanks in large part to how the fallout over the Battle of Sokovia will really be catching up with the team in Captain America: Civil War and beyond. However, as a character, he still felt pretty underused. Rather than being the birth of a new major, recurring villain for the MCU to stand shoulder to shoulder with a character like Loki, Ultron's age lasted only a few days before coming to a close. After being locked out of escaping into the internet, the final bit of Ultron was seemingly defeated for good by Vision, though the moment is ambiguous enough to leave open many possibilities, like his consciousness once again being returned to the Mind Stone. James Spader did a pretty solid job bringing the character to life, and it'd be disappointing to not see him have the chance to carry it further, especially considering the fact that Ultron's comic counterpart has frequently resurfaced again and again to be a thorn in the Avengers' side.