10 Avengers Who Should Join The MCU Next

Marvel's homage to Golden Age superheroes was introduced in 2000 via a fun gimmick of pretending that he was a forgotten creation from the early days of the company, with mockup artwork to match.

This also played into Sentry's origin. Robert Reynolds drank a serum that gave him the power of "one million exploding suns" and turned him into a man of some kind of durable metal. Sentry was one of the Marvel Universe's first heroes and shared close bonds with other characters like Hulk and Spider-Man. However, years later, when Sentry tried to warn the rest of the superhero community of the return of his nemesis the Void, he found that no-one had any memory of him ever existing.

Eventually Robert discovered the truth that the Void was his split personality and Sentry had used his powers to erase himself from everyone's minds to protect them from him.

Sentry battled with his evil persona for a number of years, but eventually fell fully under the Void's control. He waged war on all of his former friends and nearly destroyed Earth until Thor put him down for good (well y'know, until he came back to life a few years later).

While the Sentry's story kind of fell apart as the comics flip-flopped over how in control he was, it's a tale that could easily be condensed down into a single film and would make a wonderfully tragic Avengers 5.