After much speculation that Chiwetel Ejiofor would join the cast of Marvel's "Doctor Strange," Deadline has learned that the acclaimed actor will star opposite Benedict Cumberbatch's Stephen Strange as Baron Mordo.

The Academy Award-nominated Ejiofor, who is best known for his lead role in "12 Years a Slave," was rumored to be up for a "key role" in the Marvel movie back in January. While the Deadline article states that Ejiofor will play Mordo when he "suits up" for "Strange," it still leaves some wiggle room regarding the actor's involvement by saying he's "rumored to be joining the film."

The report also clarifies Mordo's potential role in the film, saying that he may not necessarily be the film's primary antagonist. Deadline states that this version of Baron Mordo will be "an amalgamation of characters culled from Doctor Strange's mythology." This mash-up methodology was previously used in "Iron Man 2" for Mickey Rourke's villain Whiplash; the character's civilian identity -- Anton Vanko -- was paired with Whiplash, a separate Iron Man villain.

Additionally, the Deadline article cites Tilda Swinton's role as the gender-and-race swapped Ancient One as another example of a character that's been altered for inclusion in the Scott Derrickson-directed "Doctor Strange." Swinton's involvement, like Ejiofor's, has yet to be confirmed by Marvel.

"Doctor Strange" opens on November 4, 2016.