Deadline reports (the online trade unusually writes they have "learned definitively") that Chiwetel Ejiofor, who was previously rumored to be playing a role in the 2016 Doctor Strange film, has been confirmed as playing Baron Mordo. Marvel Studios has not confirmed this casting.
Baron Mordo is one of Doctor Strange's principal adversaries in comic books, as a scorned pupil of the Ancient One who becomes Doctor Strange's adversary. Deadline's report, however, states that Mordo isn't necessarily the film's villain or that he'll even be an antagonist for the film. Citing unnamed sources, Deadline says Ejiofor's Baron Mordo role is "an amalgamation of characters culled from Doctor Strange's mythology." There's no word, however, on which characters outside of Baron Mordo those would be.
Ejiofor earned an Oscar nomination for his lead role in 12 Years A Slave.
Doctor Strange is scheduled for release November 4, 2016.