Never-before-seen unused concept art from Avengers: Endgame reveals Iron Man (Robert Downey Jr.) and Doctor Strange (Benedict Cumberbatch) switching battle costumes. Two of the quippiest characters in the Marvel Cinematic Universe came together in Joe and Anthony Russo's Avengers: Infinity War, as the heroes prepared for the imminent arrival of Thanos (Josh Brolin). The pair spent a lot of screen time together - from fighting Maw and Cull Obsidian in New York to experiencing The Decimation in Titan. But along their adventure, fans could've seen them donning each other's respective suits.
Tony Stark and Stephen Strange almost have the same origin story. Both were at the height of their careers and living lavish lifestyles when tragedies altered the course of their whole lives, leading them to assume their superhero persona. In terms of personality and characteristics, the pair also has some notable similarities as they're intellectually-gifted and extremely sarcastic. Which was why seeing them come together in Infinity War was such a treat for die-hard MCU fans.
The pair's then-budding relationship as fellow heroes would've been elevated in an unusual way as revealed in new concept art shared by Reddit user Steve32767 featuring the heroes wearing each other's battle gears. Doctor Strange can be seen wearing Tony's nano-tech suit, while Iron Man dons the Cloak of Levitation. While the illustrations come from "Avengers: Endgame - The Art of the Movie," the scene depicted imply that they're supposed to take place in Infinity War as the pair, alongside Peter Parker/Spider-Man (Tom Holland) found a way to get rid of Maw. Check out the images below:
Since Strange was part of the unfortunate half of the universe who were dusted off via Thanos' deadly snap, he and Tony didn't get to spend much time together until the latter's tragic death in Endgame five years later. They did have two interactions in Avengers 4, but with the climactic battle taking place, there's not much they can say to each other. In any case, the rapport that they developed in Infinity War was enough for fans to want to see more of them sharing scenes together. Chances of that coming to fruition are very slim with Iron Man dead, but with the sorcerer's ability to travel through time and place, he can reunite with his fellow New Yorker at a different setting.
With Avengers: Endgame capping the stories of some of MCU's cornerstone heroes, it also marked the beginning of transition when it comes to the franchise's top-tier heroes. Unlike Steve Rogers (Chris Evans) who passed the shield and effectively the Captain America mantle to Sam Wilson (Anthony Mackie), there's no clear successor to Iron Man's persona. Spider-Man: Far From Home dabbled with this idea with Peter being the next Iron Man. It's safe to say that it won't be the case considering that the web-slinging hero's time in the universe is limited, But Marvel Studios is just looking for someone similar, Strange seems to be their best bet considering his string of similarities with Tony.
Source: Avengers: Endgame - The Art of the Movie (via Steve32767)