Marvel Cinematic Universe: 10 MIA Villains Who Need To Return

Last Seen: The Incredible Hulk

Perhaps the franchise's oldest, biggest loose end is the fate of Samuel Sterns, the character's final on screen moments back in 2008's The Incredible Hulk teasing his future as the Leader as the character began undergoing a mutation thanks to Bruce Banner's blood entering a head wound he had suffered thanks to Emil Blonsky.

Since then, a decade has gone by and the character has yet to reemerge, which is unfortunate - though unsurprising - as the film he was introduced in is sort of a black sheep entry in the franchise at this point. Fortunately, however, the return of General Ross in recent years has suggested that Marvel Studios isn't entirely averse to bringing the events of and characters from that film back into the fold, which makes it easy to keep one's fingers crossed that the character - and fans - can one day see some closure.

Even if Sterns isn't fated to do battle with the Hulk on the big screen, actor Tim Blake Nelson isn't one to turn his nose up at television roles, and if the films can't find a place for his return, it's hard to imagine he wouldn't make for a good villain for the Agents of S.H.I.E.L.D. to have to deal with in a future season. Not only would it give Nelson more time than a film would allow to truly sink his teeth into the role, flashbacks could help get us up to speed about what he's been up to over the years, all while giving us some long-awaited answers and the team a unique antagonist to take down.