It's learned, instead of the dreaded Domammu, the Doctor Strange movie originally had a different villain.
Director Scott Derrickson revealed an earlier idea featured Doctor Strange taking on Nightmare, who similar to Dormammu, is also the ruler of a different dimension, with the Dream Dimension.
“Kevin made a very cogent case,” Derrickson said. “The trouble with starting with Nightmare is getting across the idea of the Dream Dimension as another dimension. The movie was challenging enough. It's already an exposition-heavy movie... Dormammu made the most sense. And he is the most present villain in the comics.”
Nightmare also happens to be a villain of Ghost Rider.
"Doctor Strange" is directed by Scott Derrickson starring Benedict Cumberbatch, Rachel McAdams, Tilda Swinton, Benedict Wong, Chiwetel Ejiofor and Mads Mikkelsen.
Marvel’s Doctor Strange follows the story of the talented neurosurgeon Doctor Stephen Strange who, after a tragic car accident, must put ego aside and learn the secrets of a hidden world of mysticism and alternate dimensions. Based in New York City’s Greenwich Village, Doctor Strange must act as an intermediary between the real world and what lies beyond, utilising a vast array of metaphysical abilities and artifacts to protect the Marvel cinematic universe.