10 Most Believable Avengers 4 Fan Theories
8. The Stones Have To Be Destroyed
The Theory
A lot of speculation has been published across the Internet concerning what happens at the end of Avengers 4 and specifically what will happen once Thanos is defeated. In the comics, the Infinity Gems are handed out to Guardians to protect them and keep them out of the hands of villains, but it wouldn't just be a case of out of sight, out of mind in the MCU. There needs to be a firmer solution.
With the Time Stone affording its user the chance to mess with the timeline and other Stones basically nerfing even the most powerful heroes, the Stones are simply too powerful not to be permanently destroyed. And that's where Avengers 4 is headed, according to one train of thought.
Why It's Believable
We've already seen hints in the MCU about the Stones being destroyable. Even though Thor failed with Mjolnir, The Avengers establishes that an Infinity Stone can be stopped using something of equal power (itself or - presumably - a sibling Stone) and Vision confirms in Infinity War that Scarlet Witch can destroy the Mind Stone because she's powered by it. So there's precedent there.
And there's no way Marvel would leave that sort of loose end open when it basically trumps all of their potential future plans. Nothing can have lasting impact if the heroes are aware of a Stone that could single-handedly defeat any villain.