Avengers: Infinity War Theory - How An Infinity Stone Could Explain Mutants And The Fantastic Four

2. Marvel's Need For Change

What if those repeated warnings about the MCU changing fundamentally for Phase 4 are a lot more literal than we've been taking them for? What if Kevin Feige has secretly been telling us the end of the Infinity Saga as well as what happens next in a very cheeky way.

Right now, Marvel are faced with the need to shepherd out the old guard, streamline the properties they count as "active" and make room for more new characters (not just the X-Men and Fantastic Four either). They need something that doesn't just kill off those characters (because it wouldn't fit the Disney approach to story-telling, no matter how much we're being told to expect huge emotional costs). What the need is a magically clean slate that gives closure on some characters respectfully enough while leaving others to move forward.

Imagine how valuable the idea of a device that would allow them to achieve that AND introduce the Fox properties in one fell swoop would be. That's exactly what we're looking at with the Reality Stone, and it's easy enough to do it, but having SOMEONE (maybe even Thanos) change reality in such a way that Phase 4 really is a different universe. And one that has mutants and superheroes living together.