Avengers: Endgame screenwriter Christopher Markus explains why they broke the Mjolnir rules for Captain America. Cap had a pretty major role, especially during the climactic battle at the conclusion of the movie. One of the most epic parts of the whole thing comes when Cap is able to take on the power of Mjolnir as his buddy Thor proudly looks on, muttering that he knew it.
However, it does go against some of what we have learned about the mighty hammer in the Marvel Cinematic Universe so far. Markus had this to say about bending the rules for Captain America.
"There was certainly a debate at one point because particularly in Ragnarok, it establishes that Thor can summon the lightning without the hammer. I think Odin even says, 'It was never the hammer.' And yet Cap summons the lightning with the hammer. You get to those things and you're like, 'It's too awesome not to do it! We'll talk about it later.'"
The scene was so epic that most MCU fans didn't really even second guess it, though it did spark a debate amongst some of the more hardcore fans online. Whatever the case may be, it seems that Christopher Markus, Stephen McFeely, the Russo Brothers, and Kevin Feige were into adding things to Avengers: Endgame for the fun of it. In addition to Captain America and Mjolnir, the battle scene included another moment that the screenwriters thought would be fun to throw in.
When most of the female superheroes are seen in one shot, that was something that Christopher Markus and Stephen McFeely thought was too good of an opportunity to pass up. They knew that some MCU fans would think that they were pandering to the female audience, but it was something that they wanted to see, so they included it during the final battle sequence and it has started rumors of a female-led MCU movie.
Thor has learned a lot about himself over the course of Ragnarok, Infinity War, and Avengers: Endgame. He has also gone through quite a bit in the last three movies, which led to his depression and weight gain. When discussing the upcoming Thor: Love and Thunder, director Taika Waititi was unsure of whether or not they were going to keep the character in his latest body transformation or if they were going to go back to the God of Thunder physique.
Avengers: Endgame is now the highest grossing movie of all time and a crowning achievement for Marvel Studios. It's also a huge win for the comic book genre in general. The fact that Christopher Markus, Stephen McFeely, the Russo Brothers, and Kevin Feige are still getting asked about different aspects of the movie is pretty amazing. The interview with Markus and McFeely was originally conducted by Slash Film.