With Strange trapped on Earth-838 at the beginning of the final act, Michael Waldron had to find a way to bring his titular hero back to where Wanda wreaked havoc – Earth-616, the version of Earth where the main continuity of the Marvel Cinematic Universe exists . However, the problem he faced was that Strange cannot use a variant of Dreamwalking, an ability granted by Darkhold that allows one to possess alternate selves in other universes. Since our main strand is from Earth-616 and he is now on Earth-838 using the Darkhold, there is no way he can dream there. So Waldron had to come up with a plan.
“Trying to figure out how we were going to get Strange into Act 3 to fight Wanda on Mount Wundagore was quite difficult,” he told ScreenRant. “Ultimately the solution was that he would own his own corpse. When we came up with that, it was a real eureka moment.” Waldron added, “But that was, gosh, multiversal travel is so hard. It has to be hard – it has to be an impossible thing that only America can do. That meant when Stephen was stranded in a multiverse, in a different universe without America, he really was stuck for a while. And me too.”
Zombie Strange was one of the best things about Doctor Strange in the Multiverse in Madness and showed how badly Waldron really wanted it to feel like a Sam Raimi film. “That was my goal,” he recently told Looper. “I knew what I needed to do for the MCU, but I tried to make him as successful as possible in his Sam Raimi way.”