2) Mad Mads Mikkelsen
If Mordo is being recast as an ally – or, at least, his switch to the bad side is being held off until a sequel – then Mads Mikkelsen will be the sole villain of the movie. If we didn’t already know that he had been cast as an antagonist, the crazy shots of him warping some kind of temple around him in the trailer would have told us.
As yet, it has not been revealed who Mikkelsen is playing, though the chief suspects are Nightmare and Dormammu. In the trailer, we can just about see the weird cracked skin around his eyes that was also glimpsed when he was filming with Cumberbatch and Ejiofor in New York. This would suggest he is Nightmare more than Dormammu – but it could be a clever bit of misdirection.