DC Studios co-CEO James Gunn celebrated his 60th birthday yesterday, and he's just shared a behind-the-scenes photo from the set of his Superman sequel, Man of Tomorrow. However, upon closer inspection, we see Lex Luthor actor Nicholas Hoult alongside an actor whose face has been hidden. Set photos for the movie have shown Superman battling a War Suit-clad Lex Luthor, but Brainiac has been kept completely under wraps. Gunn hasn't cast a particularly well-known actor in the role, though many fans are banking on Man of Tomorrow delivering a fully comic-accurate Brainiac. In Man of Tomorrow, Superman will be forced to team up with Lex Luthor to battle Brainiac, a threat not just to Metropolis but to the entire world.