Now that some of the Craziness has died down a little, I thought I would layout the story line from what I personally think is going to play out throughout the rest of the Marvel Cinematic Universe. Starting from Avengers: Age of Ultron and ending with Avengers 3.
As a reminder I want you to know that all of this is pure speculation. So don't think that this is all factual cause I can be 100% wrong.
So lets start with [The Avengers: Age Of Ultron](movie:293035). At the end of that film I think Tony Stark is going to feel so ashamed and so torn up by creating Ultron. Ultron is a global threat and he is going to be giving the avengers a run for their money. What's interesting is that at the end of the movie, Tony is going to realize that by spending his time trying to protect the world from the dangers that lie beyond our planet, he is the one who brought it to near extinction.
Joss whedon has confirmed that an avenger will die in this movie. No matter who that is, it is going to have strong effect on tony because he was the one who created Ultron. We also know that there are scenes involving Iron man vs hulk, and a scene where Thor is choking Tony. So, clearly The Avengers are not happy with what tony has done by putting the world at stake. But after all the dust has settled and Ultron is destroyed, the government will step in and say these heroes need to be controlled.
Enter Captain America 3: Civil War ( I don't think it will be called fallen son cause I don't think cap is going to die) At the start of civil war, the world will be recovering from the devastation left by Ultron. Also, the government will announce the super hero registration act. As I said before Tony is going to feel so ashamed and so filled with guilt that by the start of Civil War he is going to not only agree to the Registration Act but also be a sole leader of it. Why? because he feels that if he can create something like Ultron, a machine that brought the world to the brink of extinction. Imagine what someone like, Thor, Hulk, and yes even Cap could do?
Tony is going to want to keep something like ultron from ever happening again. So he allies with the government to have it where the avengers work for them. Instead of the Avengers being independent they are going to become slaves of the government. Cap see's this as a very bad thing cause he's been shown first hand of what the government's intentions are and how corrupt they can be especially after the events of Winter Soldier.
This can cause a great deal of conflict between Captain America and Iron Man. Cap fights for freedom for all and that the world needs heroes like them to make people feel safe. Tony just doesn't see it that way and in his mind if your not with him your against him. So in essence Iron Man will be the villian of Captain America 3. This will cause Cap to go on the run and gather up his "Secret Avengers" that he is rumored to have at the end of Age of Ultron. They along with a team that Tony has assembled will go to war that will carry over to Avengers 3.
Now we arrive at Avengers 3 and the Civil War is still going on. But, how does Thanos fit into all of this? Well, what if the whole time the Civil War was going on, Thanos was secretly gathering all of the infinity stones? Seeing as how the heroes on earth were too busy fighting each other that they didn't pay attention to the biggest threat that can not only destroy their world but the universe.
Now in Guardians of the Galaxy 2 which takes place after Avengers: Age of Ultron, you can show Thanos trying to acquire the Infinity Gauntlet. At the end of the movie he succeeds and with the power of the Gauntlet, All of the Infinity Stones come to him at once from across the universe. He then begins rampaging across the galaxy destroying world after world planet after planet and he has his sights set on earth. Peter Quill and the rest of the guardians see this and set out on a journey to warn the avengers.
Now back to avengers 3 while the heroes are still fighting among themselves, the guardians show up and try to convince everyone that Thanos is coming to destroy the earth. But, they are too late and Thanos touches down on earth killing and laying waste to civilians and heroes.
Once Iron man and Captain America see the devastation Thanos is causing they can put their differences aside for the greater good which in a sense everything comes "Full Circle" because that is the sole reason for why The Avengers were brought together in the first place. The world is in danger and the people NEED them. So, The Avengers team up with the Guardians of the Galaxy to take on Thanos in an Epic Final battle in which The Avengers save the world and the Guardians go back to protecting the Galaxy.
Now like I said before this is purely what I think is going to happen. I could be 100% way off but i just thought it was a pretty cool concept to how thanos and civil war could happen at the same time. But, Let me know what you guys think in the comment section below.