I am a new contributor and relatively long time reader of Moviepilot articles. This is a theory that I've been mulling over for the last few months which stemmed after watching the Avengers: Age of Ultron film. I want to note that this theory, as noted by the title, branches into two distinct sections that I will address individually because they are independent of each other: the tentative basis for the plot of Infinity War Parts I and II and a potential outline for the overarching plan of MCU Phases 4-6 starting with Inhumans in 2019. I am open to criticisms of my theories and anything that can better strengthen the theory will be edited later (you will also be credited for your contribution).
So this should go without saying, but just to be safe:
[Spoilers Ahead: This applies to Avengers: Age of Ultron among other MCU films, Agents of S.H.I.E.L.D., and potentially several future Marvel films.]
Theory A: The Infinity Stones and Thanos's Cabal
An important note before I dig into this: I did not originally form this concept myself. This is the addition of a previously develop theory which lead to the concept of a larger theory - the one you're about to read. You can find the original theory here. (it's a small part of the theory that in turn became the partial basis of MY theory.) I understand that it's unprofessional or at the very least annoying to see a theory based on a theory, but this is more of an expansion on a theory. Regardless, please take time to consider it before jumping straight into criticism.
So the basic premise is simple: When Thanos collects all 6 of the Infinity Stones, he decides to build a Cabal of six members to rival the Avengers. Now, the Cabal is not an unheard of concept; however, this would be a different Cabal than the one found in the comics consisting of members from previous films:
Space Stone: Red Skull
While it is important to note that the original actor has expressed a lack of interest in returning to the role, that does not exclude the possibility of recasting the Red Skull. When last seen, the Red Skull was pulled into a portal of some kind created by the Tesseract (which houses the Space Stone). The potential here, is that Red Skull is somewhere within the MCU and can be picked up by Thanos at any time to be recruited to get revenge on Captain America.
Mind Stone: Ultron
Another character whose fate is obscured, Ultron. As noted in the previously linked article, the film cuts away and we only see a flash of light when Ultron lunges at Vision. Taking cues from the conversation, Vision holds no hatred or anger towards Ultron and instead seeks to potentially reform him, if at all possible. Immediately after being brought to life by Thor, Vision states that, "I don't wish to kill Ultron. He's unique . . ." This seems to point to the idea that Vision did not end Ultron, but instead used the Mind Stone to subdue him. Thus, the idea is that when Thanos activates the stone, he will be able to resurrect Ultron and add him to his Cabal. This would also make sense from a studio stand point because Ultron as a character is very different from the other villains. Throughout the movie, he shows flaws - specifically his anger and extreme desire to separate himself from his creator, Tony Stark. But that's a different matter for a different post.
Reality Stone: The Collector
While his museum may have been destroyed as a result of the Power Stone being activated, the location of the Aether is unknown. Also important to note, the Aether, though given to The Collector after the events of Thor: The Dark World, the Aether was not on display. Given the high price The Collector was willing to pay for the Orb, it is likely that he had the Aether locked away. Thus, it's fair to say that he will attempt to bargain with Thanos for a position in his Cabal to get revenge on the Guardians for destroying his museum.
Time Stone: Baron Zemo
Baron Zemo has been confirmed for Captain America: Civil War. How he fits in is yet to be determined. However, he supposed to be the main villain of the film which could point to him assembling the Thunderbolts with General Ross. The Avengers could turn on him when they discover his less than humane method for converting unregistered heroes and villains. During his travels, he may also happen upon an Infinity Stone and give it to Thanos, granting him the support of Hydra, assuming Zemo is the MCU head of Hydra instead of connecting it to Agents of S.H.I.E.L.D.'s Hydra characters.
Alternative (as suggested by Antonio Aranibar): Baron Mordo
Baron Mordo's role in Doctor Strange is yet to truly be determined. In regards to his character, he has been described as a person that walks a line between antagonist and protagonist with an implied shift to one side over the course of the film. So, assuming he does become a full villain as he is in the comics, Thanos would want him in the Cabal. The items from which the stones can be found vary greatly (as noted by the title graphic), so the stone being part of a relic in the Sanctum Sanctorum is a better explanation than what I could come up with for Baron Zemo. I will be the first to admit that that prediction is extremely questionable and this theory definitely holds more credibility.
Soul Stone: Loki
It's almost guaranteed that Loki will join Thanos's Cabal. He's a fan favorite, the only villain to find himself in a recurring role, and the first person to be used by Thanos to begin instituting his plans for domination. While it can be argued that his current position as head of Asgard (as noted at the end of Dark World) would grant him access to the Tesseract, the events of Ragnarok could lead to the discovery of the Soul Stone. This would allow him to make amends for his failure during The Avengers by returning with two Infinity Stones.
Power Stone: Thanos
In the post-credits scene of Age of Ultron, we see Thanos grabbing his own Infinity Gauntlet and vowing to "do it myself. [sic.]" Given how powerful Thanos is even without the gauntlet along with the Kree and Chitauri armies at his dsposal, he could easily attack the Nova Corps and take the Power Stone from them. This would be a great way to start Infinity War Part I because it shows the power Thanos has even without the gauntlet and shows him to be formidable opponent after spending 6 years sitting in a chair ominously.
Ultimately, having collected all of the stones and activated them with the gauntlet. Thanos will build his Cabal and plan to siege Earth. This would be the best way to end Part I because it leaves audiences with an intense cliff hanger and allow more time for fans to speculate over the next year.
Theory B: Phases 4-6 - The Secret Invasion, The Kree/Skrull War, and H.A.M.M.E.R.
I will admit, some aspects of that theory are a bit difficult to believe. However, I have more confidence in this theory due to the rich stories created by the comics and subtlety that has been instituted in regards to these stories. It's also extremely possible that I'm reading way too deeply between the lines and just projecting what I want to see as a comic book fan. But at any rate, it is my belief that Phase 4 will see Norman Osborn assembling H.A.M.M.E.R. in response to the collapse of S.H.I.E.L.D. in Winter Soldier, the Secret Invasion being teased throughout Phase 5, and the Kree/Skrull War being the main conflict split into two parts at the end of Phase 6 much like the Infinity War.
Still curious? Great, I know these stories may not be as well known to some new comic fans or just fans of the comic book films, so allow me to elaborate on each of these stories and how they can be best adapted to the MCU:
H.A.M.M.E.R. and Phase 4
The organization whose acronym bares no significance, H.A.M.M.E.R. was established by none other than Norman Osborn. Recently, Marvel begrudgingly gained the rights back to Spider-man, albeit through a deal of sharing the property with Sony. It's safe to assume that Norman Osborn will be introduced in the solo Spider-man filmed slated for July of 2017.
Now, in the comics, S.H.I.E.L.D. was disbanded in the midst of The Secret Invasion, so the timeline for the MCU is a bit different. However, it's important to note that S.H.I.E.L.D. has already been disbanded in the MCU and any attempt at rebuilding iin the TV series has been met with skepticism. Thus, it would make sense that Osborn would step in to create H.A.M.M.E.R. in response to a lack of authority on S.H.I.E.L.D.'s part. This could then lead to a form of the "Dark Reign" event wherein Avengers 4 involves the removal of Osborn from power and a consolidation of S.H.I.E.L.D. The ramifications of this would be directly felt on the show Agents of S.H.I.E.L.D. and provide a strong link between the TV universe and Cinematic universe.
The Secret Invasion of Phase 5
With the contracts of our core Avengers expiring with the conclusion of Infinity War, it's important to ask the question: So what now? Obviously, that's the point of this theory, but what's interesting is that our big three Avengers are willing to come back. Robert Downey Jr. has expressed interest in returning in a more minor capacity. Meanwhile both Chrises (Evans and Hemsworth) have expressed a desire to continue in their respective roles.
The Secret Invasion can serve to answer two key questions: How do we appease the fans' desire to continue seeing these heroes that they love without recasting and what happens to these characters when the actor contracts expire? The Secret Invasion would offer a chance to see these characters return in either a major or minor capacity to set up the Kree/Skrull War of Phase 6. This also allows Marvel to keep these characters on hand instead of killing them and having to utilize a retcon as is the case with the comics.
If you're confused, let me save you a google search or two. The Secret Invasion is an event that leads to the Kree/Skrull War wherein a race of aliens known as "The Skrulls" impersonate various characters within the Marvel Universe. The Skrulls are enemies of the Kree Empire and are capable of shape-shifting to impersonate anyone and everyone. With this ability at their disposal, they invaded Earth as well as S.H.I.E.L.D., ultimately turning Earth into the battlefield of a war between the alien races.
I don't know exactly how this would work for Phase 5. Maybe just small cameos here and there that lead to some characters asking questions they don't they shouldn't be asking. Maybe the heroes come in to lend a hand fighting, say Dormammu following the events of Dr. Strange 2 or 3. Either way, there needs to be some planning involved for the big reveal in Part I that the Secret Invasion started in Phase 5 or even earlier if they can script it right.
The Kree/Skrull War Part I and II
I'm almost certain that Marvel has been building towards this. Either that, or the writers are borderline obsessed with the Kree. First, in Agents of S.H.I.E.L.D. Season 1, it's explained that a chemical synthesized from the blood of a Kree warrior was used to resurrect Coulson and later Skye. This leads to the discovery of Kree ruins and the Terrigen Mist in Season 2. Now in Season 3, Inhumans are confirmed to exist even though they won't be officially added to the MCU until 2019. The Inhumans were created by the Kree and Captain Marvel's origins involve the Kree as well. The Kree were officially introduced as an empire in Guardians of the Galaxy with Ronan the Accuser, so that helps set up Captain Marvel.
Some may immediately say that this is due to the fact that Marvel doesn't actually own the rights to the Skrull because the Skrull are owned by FOX as part of their control of Fantastic Four rights. This, however, is not necessarily true. While FOX most likely does hold the rights to the Super Skrull, Kevin Feige pointed out that both companies hold the rights to the Skrull back at the Avengers premiere in 2012 when there was still speculation on what alien race Loki controlled.
So maybe the idea here is that the Skrull are not acknowledged to thus make it more of a shock to both the characters as well as the audience when they make their surprise appearance in Phase 6 in time to fully launch the Kree/Skrull War on Earth and better introduce the Inhumans to the MCU.
Or, again, I could just be completely wrong about all of this and there's actually no real plan for Phases 4-6 at the moment.
Anyway, that's my tentative plan for Phase 3-6. Hopefully the small fraction you spent reading this was worthwhile in some way. If you have anything to add or correct, feel free to let me know. Any useful feedback is greatly appreciated!
Updates to Theory A can be found here (more to come):
Updates to Theory B can be found here (more to come):