It will be released in theaters in a few days Avengers: Infinity War. We know a lot about the plot and have enjoyed guessing what we're not sure about yet. Everything revolves around that face that we saw for a few moments at the end of the first Avengers in 2012. It was the first appearance in the MCU of the Mad Titan, more known by the name of Thanos. One of the most powerful beings in the universe, formidable and indestructible fighter, as well as completely mad.
Do not think you are facing the usual villain in search of power. His plans are much more articulated and complex. It is the threat of which Tony Stark he suspected the arrival, but of which he knew nothing; why, even before that Thanos declare war on the inhabitants of the Earth, the mind of the philanthropist billionaire had conceived Ultron (with catastrophic results to say the least). The characters of any story clash with each other because in one way or another they are convinced that they are on the right side, as in the case of Captain America and Iron Man in Civil War, for the reasons we know well. The same goes for the antagonists of the heroes. They are convinced that their success depends on the realization of their (distorted) vision of the reality in which they live and which generated them.
The reality that made it Thanos what we know is merciless. Up Titan (Thanos place of origin), many years before that Loki unleashed i Chitauri around New York, society and the lives of the inhabitants of the planet were put to the test. The population had increased dramatically and the resources were insufficient to support everyone. Titan's fate was sealed, but Thanos proposed his solution to the problem: eliminate one half of the population to ensure the survival of the other. A plan that is as simple and mathematically concise as it is insane. Needless to say, the other inhabitants of the planet did not accept the proposal with enthusiasm. Thanos he was exiled, and the poor people left on Titan met their own tragic fate.
Completely abandoned the last shreds of reason, Thanos he devoted himself to what he has ever considered his mission: to restore balance to the universe, and perhaps even correct his own mistakes. He is convinced that to do this he must wander in space and eliminate 50% of the living beings of the planets he encounters in his path. Learned about the power of Stones of Infinity decides that it is time to take possession of the legendary artifacts and use them immediately against the inhabitants of the Earth. 
In defense of the Terrans, however, the Avengers, and the Infinity War it will start. With these premises it is clear that we are faced with a complex character, deeply convinced of what he does. That's why all the Avengers and all their allies to fight it. We are not dealing with an intergalactic criminal, a mere thief of relics. Thanos it represents not only the fears of the protagonists, but also their weaknesses. He alone is capable of rivaling the full superhero team in strength. For this it will be Thanos to tell the story of the film. There War of the Infinite it will be shown to us from his point of view. To defeat this threat, the heroes must first understand it, enter the mind of the madman, find themselves in that madness and come out better. Thanos is the threat of which the Avengers they need.
Watching the film from this perspective could show us a lot of what will be overshadowed by the many action scenes. The point of view of Thanos will probably (or at least hopefully) be the tool that will allow the Marvel Cinematic Universe not to implode, turning in on itself and confining itself to genre cinema. It will be the villain who dictates the pace of the narrative and he will always allow characters who have not yet met to be firmly united. Thanos will be the yardstick with which we will measure Infinity War.
