10 Unused X-Men Villains MCU Phase 4 Could Introduce
4. Stryfe
Who? The clone of Cable. So if you know Cable's storyline, then you know Stryfe is just as complicated. But the basics are: he's a mutant possessing psionic abilities, he was created when Cable was brought to the future after being infected with a techno-virus, Stryfe was then stolen and raised by Apocalypse. Because he was never infected with the virus like his (twin?), Stryfe has greater control over his powers. Being raised by one of the worst beings in comics...pretty much guarantees you grow up to be a bad guy too.
Also, he wears ridiculous 90's designed armor.
How he fits in the MCU: Deadpool. We still have yet to determine how much of Deadpool-verse becomes MCU continuity, but let's just say that Cable is along for the ride. Feige could decide to get totally crazy and dive fully into the Summers-Grey storylines, expanding on Cable's origins and all of its complications. Get into all the time-travel, clones, siblings, offspring, relationships, and all the while hint at the coming of Apocalypse for a later movie.
Also, design something better than Ivan Ooze. Stryfe gets to be the major villain for the first part of this saga. Awkwardly, does that mean Josh Brolin returns as Cable...and Stryfe? Can he be 3 MCU characters?