There are a lot of theories flying around about what might happen in Avengers 4, but this one looks ahead to how the events of what’s being called the grand finale of the MCU as we know it could set up the big bad for Phase Four of the franchise: Galactus.
The comprehensive theory from Reddit user @ZeekOwl91 is built on the back of his concept that the Mind Stone has secretly been helping the Avengers all along as well as the notion that Asgardian society was created by the Infinity Stones, thereby making them the source of Thor’s powers, too. The fan kicks off his argument by saying that the God of Thunder’s visions in Avengers: Age of Ultron were meant to prepare him for the turmoil to come.
This thought also brought to mind the visions that Thor had in Age of Ultron, the visions he saw of the Infinity stones. I had written this theory that the Mind Stone had been helping the Avengers from the beginning, and in it I mentioned that Wanda could be a vessel for the Mind stone, which means that it was the stone showing these visions to Thor. At the end of AoU, Thor mentions that the Mind stone is the fourth of the Infinity stones to be found and that there’s someone who’s made pawns of them and bringing the stones up. The prevailing theory is that this was Thanos’, but it could have been the Infinity stones(specifically the Mind stone) pulling the strings in a way as well.
The goal of the visions were to push Thor towards claiming the Infinity Stones for himself to create a replacement homeworld for his people, following the events of Ragnarok. The theorist puts forward the idea that Asgard is important for holding back a terrible cosmic force, much like Odin was key to imprisoning Hela. As the Infinity Stones are conscious and on Thor’s side, this is why he was able to nearly best the Mad Titan in combat.
I think the visions that Thor had in Age of Ultron were partly about Ragnarok, and the Mind stone could have been trying to tell Thor about creating an Infinity Gauntlet, in order to create a “New Asgard” with it after the events of Ragnarok(but instead it went with creating Vision in order to deal with Thanos first). I believe when Asgard was created by the first King, it wasn’t just the seat of power for their family, but it was also the power that helped keep a greater(and ancient) threat at bay.
The Infinity stones were driving Thor towards recreating the New Asgard with an Infinity Gauntlet to restore it to power and continue holding off this ancient threat, but Thanos perverted the initial design and purpose of the Infinity Gauntlet for his own gains and vision, which is why it was fried and damaged at the end of Infinity War: He used it as an Instrument of Death, when it was originally meant to be one that defended Life! I think this was also why Thor was able to use Stormbreaker to cut through the blast Thanos threw at him with the power of all six Infinity stones: It wouldn’t cause harm to an Asgardian King, since the first one designed and created the original Gauntlet!
Finally, the theory ends with the possibility that the damage Thanos has caused to reality, plus the absence of Asgard, could release Galactus himself from his prison in the Quantum Realm, which we know will play a role in Avengers 4, thanks to Ant-Man and the Wasp’s post-credits scene.
Thanos’ misuse of the Gauntlet would have sent the universe into utter chaos, but the Avengers will prevail. But, his actions, coupled with the destruction of Asgard(and with it, the force to hold back whatever’s coming), could spell the untimely release of a much greater threat than anyone would have anticipated. If I were to guess, I think it would have to be Galactus(probably getting released from the Quantum Realm), but you can put whoever you want in that spot, because, well, this is all just a theory, hahaha!
This is an intriguing idea. After all, Galactus has to be one of the top characters that Marvel wants to bring into the MCU. However, as we’ve heard several times already, it’s probably too soon for the Disney/Fox deal to have any impact on Avengers 4. Still, we’ll hold out hope and with any luck, next March’s Captain Marvel will bring us some more answers.