On Sunday, director Zack Snyder held a virtual viewing party of Batman v Superman: Dawn of Justice. Snyder offered a live director's commentary of the film via VERO, talking through some of the finer points of the movie. Among them is Harry Lennix's role in the movie. Lennix played General Calvin Swanwick in Man of Steel. By the time Batman v Superman takes place, Swanwick is Secretary of Defense. But Snyder already revealed that he intended to show in Justice League that Swanwick is the Martain Manhunter in disguise. During the viewing of Batman v Superman, he discussed the role in more detail.
"Harry Lennix is pretending to be a human being but does a great job, but has this relationship with Lois that started in Man of Steel if you kind of track their relationship," Snyder says. "Harry understands there's a relationship between Lois and Clark, who he knows, of course, is Superman."
Martian Manhunter's story is like Superman's in that they are both the lone survivors of their respective homeworlds. They both pass for human on Earth, though in the case of the Martian Manhunter, a.k.a. J'onn J'onzz, blending in requires shapeshifting. J'onn is also telepathic, which explains how he knows Superman's secret identity. It is easy to understand why J'onn would sympathize with Superman and keep his secret.
Martian Manhunter is also a founding member of the Justice League in the DC Comics universe. In a previous post, Snyder revealed the storyboard for a Justice League scene where Swanwick transforms into his Martian form. Snyder stated that he filmed the entire scene except for Lennix's shots, which would have filmed later in Los Angeles. That never happened as Joss Whedon took over filming in reshoots and altered portions of the film's plot. Martian Manhunter's cut role in the film is just one Snyder-planned moment that Justice League fans hope to see restored in a release of the Snyder Cut of the movie.
The upcoming slate of DC Films movies currently includes Wonder Woman 1984 on August 14th, The Batman on June 25, 2021, The Suicide Squad on August 6, 2021, Black Adam on December 22, 2021, Shazam! 2 on April 1, 2022, Super Pets on May 20, 2022, The Flash on July 1, 2022, and Aquaman 2 on December 16, 2022.