After seeing Thanos having a tropical hiatus somewhere in southeast Asia, within the lush beauty of terraced rice paddies, which have been confirmed as the Philippines' famous Banaue Rice Terraces, the moment seems to be short-lived. He was seen later in a new clip of the Avengers: Endgame waiting on a desolate, devastated planet, about to be confronted by Captain America (Chris Evans), Iron-Man (Robert Downey Jr.) and what appears to be Thor (Chris Hemsworth). However, it was not about how to end the battle with Thanos, but it was to end the real battle from the start, of how The Avengers was divided all along, and its all because of Tony Stark and Steve Rogers.
Since the battle is not at all physical, it was the emotional scar that needs to patch up and end the world's biggest fight, the fight within themselves. Yes, it was never about Thanos since he was only playing the role of the villain, munching on every possible way to destroy the Earth and why was he able to do so, because the Avengers were divided. In a thorough review, the conflict started when Tony Stark discovered who killed his parents in Captain America: Civil War, revealing Private Steven "Steve" Rogers' sidekick Bucky Barnes, and then the division took place right then and there, two superheroes going on different paths, because they couldn't agree on politics. Ridiculously, even in real life, old friends do part their ways because of different political beliefs and these superheroes has left the members of the Avengers all wondering to whom they are going to side with, throughout the next movies that followed.
It was a failed mission, with almost 80% of the Avengers and half of all the universe disintegrated and Thanos alive for the Avengers: Endgame. But before winning the battle with Thanos, they must win over the battle among themselves, that is between Captain America and Iron Man to fully penetrate the powerful enemy. How can they make it, now that the ones left have low morals and extreme sadness, take note that in the trailer of Avengers: Endgame, Stark was seen floating in space, waiting to die after he sends one last message to Pepper Pots while Rogers was dealing with his failure, as he fights too much but still losses a lot?
Because of so many conflicts and issues involved between the main characters, Avengers: Endgame will need 182 minutes or more or less 3 hours for them to straighten things up, making it the longest Marvel movie beating the record of 149 minutes set by 2018's Avengers: Infinity War. The moral of the story lies in the fact that these two superheroes have to reunite to save the people, those that they care about. Their issues have been their greatest enemy ever since, and if they are on a mission to save, they'll have to be selfless and united.