Benedict Cumberbatch has officially been attached to Doctor Strange since December but has not yet been given any other help in the casting department. Rumors have swirled that Daniel Brühl (Baron Zemo) will first be introduced in Captain America: Civil War before being the big bad later next year in Doctor Strange.
Thanks to The Hollywood Reporter, Cumberbatch may be getting his first co-star. According to the site, Tilda Swinton is in talks to play The Ancient One.
This is an interesting choice for many reasons. THR reported earlier this year that Marvel was looking at Chiwetel Ejiofor for a big role in the film and speculated it could be The Ancient One or a villainous role. Hopefully Ejiofor lands a role in the film as either Baron Mordo or Wong, which were both speculated roles in the original THR article. It’s also worth noting that there’s also the possibility of Ejiofor playing Brother Voodoo, as has been speculated by fans.
In the comics, The Ancient One is the male mentor to Strange and teaches him in the ways of the mystical realm. Should Marvel move ahead with these plans and get Swinton for the role, it would further diversify the cast and would bring a new element to the relationship that The Ancient One and Doctor Strange have.
Marvel has yet to make this casting choice official but when they do we will update you.
Source: The Hollywood Reporter