Marvel: 12 MCU Theories That Make Appalling Sense

10. The Chitauri Are Still Around

The Theory

The Battle Of New York wasn't actually the roaring success The Avengers might have thought, as they merely battled a fake diversionary force designed to draw their attention away from a quieter legitimate invasion.

Their real agenda was to shape-shift and replace key figures on Earth (including superheroes), deeply implanted and waiting to lead an invasion from within.

The Evidence

Well, the source material states that the Chitauri are a race of shape-shifters (the movie seems to confuse them with the cyborg-like Phalanx), and there were pretty compelling rumours in 2010 that suggested that The Avengers would star the Skrull (stars of the doppleganger-led Secret Invasion comic arc).

Could it be that the Chitauri actually used fake cybernetic avatars to attack New York while their real kind infiltrated and replaced key characters when they "died" or removing key targets themselves? It sounds far-fetched, but there was evidence from a casting all that the Chitauri might be returning for Infinity War, and their reveal would be a hell of a way to escalate beyond Infinity War to another huge event.