Avengers: Endgame originally had another big cameo from the Doctor Strange standalone movie. There's a lot already packed into the epic movie, but there was originally set to be more, according to the script. Wong was able to help come save the day at the conclusion of the movie, which Marvel Cinematic Universe fans knew was going to happen. However, it was Hulk's meeting with Tilda Swinton's Ancient One that threw fans for a loop. With that being said, the encounter was much different in the Endgame script.
The Ancient One didn't make it out of Doctor Strange alive, so MCU fans were curious as to how the character could be returning in Avengers: Endgame. As it turns out, Hulk goes back in time to 2012 in order to obtain the Time Stone from her. It wasn't an easy sell, and it was even harder, according to the script. The Ancient One did not want to give up the precious Infinity Stone because it could shift her timeline into darkness with multiple Stones being available in the galaxy.
What is exclusive to this Avengers: Endgame script is the fact that Dormammu, ruler of the Dark Dimension, was set to make an appearance. In the script, the Ancient One uses her magic to show Hulk what would happen if she gave up the Time Stone to further illustrate her point. She ends up showing the Hong Kong Sanctum burning to the ground, while hundreds of people in the nearby street run away from Dormammu, who is coming down from the sky. This would have been pretty effective, but it also sounds like it would have been a pretty huge scene to shoot.
In the end, the Russo Brothers decided against adding in Dormammu in Avengers: Endgame. Plus, in the script, the result was exactly the same, so we really didn't need to see the return of the villain to get the Ancient One's point. MCU fans will recall that the villain was beaten after some clever use of the Time Stone in Doctor Strange. In the end, Tilda Swinton was the big cameo from the movie and it was a good way to further give the character closure after seeing yet another sacrifice from her.
Doctor Strange in the Multiverse of Madness is set to hit theaters in 2021 and it could very well see the return of Dormammu and maybe even the Ancient One. It has been rumored that Benedict Cumberbatch will have a role in the upcoming Disney+ series WandaVision in the final episode to help usher in the sequel. This has not been confirmed, but Marvel Studios boss Kevin Feige has said that the TV shows will have big implications for the big screen MCU. For now, we'll just have to wait and see. You can head over to Disney Studio Awards to read and download the Avengers: Endgame script.