According to Infinity War co-director Joe Russo, Thanos served as the narrator for the third Avengers movie in one of the screenplay's early drafts. While this part of the script was cut, Thanos's narration would've made a lot of sense, considering that Thanos was treated as the protagonist of the entire movie.
Surely, Avengers: Infinity War looked like a monster to directors Anthony and Joe Russo in its early stages. The movie had to star 20+ heroes, have an impressive villain, and live up to the previous two Avengers movies. This feat was certainly accomplished well, but one can only imagine how much the Russo brothers had to go through to get from where they were in the beginning stages of the project to where they are now. The numerous main characters and story arcs were treated like puzzle pieces, with the Russo brothers finding the perfect places to put each character and where to put each arc chronologically.
While sitting down with Entertainment Tonight, Anthony and Joe Russo discussed a bit of the process that they had to go through to put the movie together, and the numerous drafts that the movie endured. Here is what Joe Russo had to say.
"There were early drafts of the script that were insane, probably had a hundred speaking parts. [There were] different approaches to style in terms of execution. One even had Thanos narrating most of the movie. So it gave us a lot of flexibility in terms of how much story we can jam into it. But at a certain point, you know, you get 20 pages into it [and] it was so dense, you're like, 'Nobody's going to be able to follow this.' So we just started stripping things out."
Anthony Russo then went a little more in-depth with the process that they had to go through developing Avengers: Infinity War. Here is what he had to say.
"It's a tough balance. We love the idea of these movies being a culmination of everything that's happened in the MCU, so our ambition as storytellers is to tell the total story and include as many characters as we can. But of course, we want to find the right balance to make sure that we're not overreaching, to make sure that the story we are telling with each character is really compelling and rich. So yeah, we do have to find that balance as we step through the script with [screenwriters Christopher] Markus and [Stephen] McFeely."
While it may have been interesting to have seen the various other drafts discussed by the Russo brothers on Entertainment Tonight in an interview conducted by Ash Crossan, such as Thanos narrating, which could have helped the story flow without having to put exposition in the scenes, it's safe to say that the finished draft we saw on the big screen was phenomenally well done. The story flowed seamlessly, perfectly balancing the 20+ main characters and making Thanos into the best villain to enter the Marvel Cinematic Universe. Hopefully this seamless storytelling will continue next year in Avengers 4.