The upcoming Thunderbolts film in the MCU Phase 5 has the potential to introduce some powerful, if lesser-known, villains to the franchise. The team has had many iterations, led by the likes of Baron Zemo and Norman Osborn in the comics. While the starting roster of the MCU's Thunderbolts team has been revealed, who exactly they'll be up against or who may join their ranks throughout the movie remains a mystery. Some subterfuge and double-crossing from the MCU's Thunderbolt's director, Valentina, could paint the CIA director as a likely twist villain pulling the strings. But the MCU's Thunderbolts still need some bombastic super-powered criminals to fight, and these lesser-known antagonists from the comics who have yet to have a true MCU debut are great candidates. In addition, with the Thunderbolts being an ever-changing patchwork team of shifting allegiances and villains trying to make the most of their circumstances, there's a strong possibility that some of these names could wind up on the team by the film's end.