When the promotions for 2017's Justice League were underway, a tagline attached to the movie in posters was 'Unite the Seven'. This led to more than a little confusion, since the theatrical release only featured six heroes, namely Superman, Batman, Aquaman, Wonder Woman, The Flash, and Cyborg. Fans have long speculated who the seventh Leaguer could be, and while the position was all but confirmed by Zack Snyder over the past couple of years, he recently came as close to an official announcement as possible, when he shared a twitter quote from actor Harry Lennix, who played General Swanwick in Man of Steel and Batman V Superman:
"Re: Justice League and the Snyder Cut...Things don't Just happen-- things happen Just."
The quote Snyder shared was featured alongside a picture of Harry Lennix as the character of Swanwick, and Snyder titled the post 'Watching over them all'. Now, if you're confused about how this post connects to the seventh Justice League member, you should know that Snyder has previously confirmed a fan theory that had been making the rounds ever since the release of Man of Steel: that Swanwick is the Martian Manhunter in disguise.
In the comics, the Manhunter is the last Martian who accidentally got teleported to Earth and became one of its champions. Among a host of abilities, the Manhunter possesses the ability to change his shape. He uses this ability to walk in society as an ordinary man, and keep an eye on the world from an intimate perspective.
From his plans for the DCEU that Snyder has shared over the years, Swanwick's reveal as the Martian Manhunter was supposed to happen in the first part of the intended Justice League trilogy. In one scene, Lois Lane comes to speak to Martha Kent. After Lois leaves, Martha turns briefly into the Manhunter before returning to his Swanwick guise.
Swanwick's presence was cut from the theatrical release of Justice League, but now that Snyder is gearing up to release his version of the movie next year on HBO Max as a four-hour special, it seems Lennix is all set to make a triumphant return, and finally fulfill the promise made by the 'Unite the Seven' poster.
It is unclear how much of a role the Manhunter will have in the Snyder cut of Justice League, and whether or not Lennix will be shooting additional scenes for the film. Apart from the Manhunter, two other heroes are rumored to be making their live-action movie debut, The Atom, and Green Lantern, even if it is in minor cameos.
Fans are excited to see what Zack Snyder has in store for them with his new cut of Justice League, even if the basic plot is something they have already seen in the theatrical version. But according to the filmmaker, what the 2017 version of the film showed audiences contained only 10% of the footage he shot, so expect there to be a lot of new additions to the plot and screenplay. This info comes from Zack Snyder on Vero.