After reviewing most of the Marvel blockbusters ( Captain America, Iron man, The Incredible Hulk) that were shown before the first avengers, I've come up with quite a theory. When the Incredible Hulk came out it was the first part to a long and linked story. The cameo of Tony Stark at the end of the credits suggested that we would be likely to see an avenger movie. These series of end credit scenes with Tony Stark was carried out throughout the (as I like to call it) pre phase of the Marvel cinematic universe. We all new there would be an avengers movie but boy was this a ride.
When the first avengers came out in 2012 we were not disappointed. The movie not only kept us on the edge of our seats but also kept us wondering, who was that big pink dude at the end of the credits? That pink dude was Thanos, one of the most powerful characters in the marvel universe. With the end credits scene we knew that there would be another avengers.
Another three years passed and in those years came out other marvel movies like captain America two and iron man 3. But the most anticipated film came at the end of those three years. Avengers 2. This time with even more action, the movie somehow topped it's prequel. SPOLIERS!
Throughout the movie we see conflict and argument between Iron man and Captain America. This opens the door to the most important Captain America yet, Civil War. For those of you who don't know what this means, it's basically a series of comics entitled Civil War (obviously) that has Iron man and his group of heroes take on Captain America and his group of heroes. Iron man fights for all heroes to have to register their hero version of themselves as people in the system meaning some heroes would have to give up their secret identity. Captain fights for the opposing reason in that their hero selves should not have to register their hero. Iron man has the government on his side as well as characters throughout the marvel universe. The ending of this civil war results in Iron man beating Captain America in a brutal battle. While the other anti registration (that's the operation name) heroes try to escape. If the Marvel cinematic universe wants to pull all this off they are going to need to bring characters and groups from other movies. Such as the fantastic four, Ant man, Spider-Man and of course much much more. We all ready know Marvel has introduced black panther to the cinematic universe and he will appear on Captain Americas side as well will Ant man (Disney expo showed us is).
Lets just go back to avengers two age of ultron for a moment. The end credits scene in this movie also included Thanos saying "fine ill deal with it myself". This gives us a clue that there will be a third and last avengers set for 2018. But what's gonna happen between Captain America and Iron man. Will one of them not be there? What's going to happen to Hulk? He took off in a little aircraft set to the unknown. Well it's sad to say this but just before the end credits there was a scene that showed us 3 heroes, Vision, and falcon. Sadly those will be on the avengers team in the last segment along with presumably Thor, black widow and hawk eye. So how does hulk tie into this? Well hulk took off on the aircraft to the unknown. My theory is that he actually traveled to a planet in which was only populated by hulks. A world of Hulks! This is where the third movie comes into play; the new avengers try to sop Thanos by going to his home planet and stoping the problem (whatever it might be) at its core. On their way they bump into a strange planet they they end up crash landing into. This planet turns out to be a planet full of hulks. And that's how they end up finding the hulk. Now this last segment of the Avengers will be linked to the guardians of the galaxy tremendously as the guardians of the galaxy included Thanos and one of the infinity stones to complete the gauntlet and all five stones. We won't see a cross over in the movies as the guardians of the galaxy will release one year before in 2017. I do think that the characters in the guardians of the galaxy will do something to help the avengers save the world. We know that both these movies are set in the same time span as each other because of the appearance on Thanos in both movies. For now all we can do is wait.