Zack Snyder kicked off the DCEU with his films Man of Steel and Batman v Superman, in which Superman (Henry Cavill) works with the United States military to defeat the likes of General Zod and Doomsday. He finds an ally in General Calvin Swanwick, played by Harry Lennix, who later becomes the Secretary of Defense. Little does Superman know, however, Swanwick is just as alien as he is.

Lennix confirmed that his character is the shape-shifting Martian Manhunter, a telepathic alien from the DC comics named J'onn J'onzz. In an interview with Collider, Lennix said he didn't know Swanwick's true identity until Justice League started filming, which was well after his first two DCEU appearances. Originally, the green-skinned Martian Manhunter was meant to appear in Justice League, so Snyder has been eagerly teasing the inclusion of J'onzz in the four-part Snyder Cut for some time now. As a fan favorite, Martian Manhunter will certainly be an exciting addition to Zack Snyder's Justice League, but only time will tell if these changes will be enough to redeem the Justice League. At the very least, fans think the trailer looks promising.