It's learned that the villain of the Justice League movie may have a different origin in the film than compared to the comic books.
According to a write-up in Geek Magazine (via Screen Rant), Steppenwolf will be the nephew of Darkseid in the Justice League movie, while it's the opposite in the comics with Steppenwolf being Darkseid's Uncle.
“In Justice League, Batman and Wonder Woman, following Superman’s death in battling Doomsday, is intent on bringing together a team to take on Steppenwolf. This new menace is the nephew to Darkseid of Apokolips (presumably the big bad of the second JL adventure). Steppenwolf is on Earth to retrieve three Mother Boxes, one of which is now a part of Cyborg.”
As noted, it could be a mistake on the part of the magazine.
I think it's actually better if, similar to the comics, Steppenwolf is the Uncle in the Justice League movie as the actor playing Steppenwolf, Ciaran Hinds, previously let it be known Steppenwolf and Darkseid are apparently not on good terms.
Hinds even reveals just what we can expect from the planet-snatching Steppenwolf, an underling to the yet-to-be-seen Darkseid. “He’s old, tired, still trying to get out of his own enslavement to Darkseid, [but] he has to keep on this line to try and take over worlds.”
I think it's a better dynamic if the younger nephew being Darkseid is in essence commanding his older uncle, which Ciaran Hinds' statement above seems to be hinting at.
Hinds also previously said Steppenwolf wants to create hell on Earth.
So basically, they’re going to concoct some kind of construction and they will use my facial expressions – eyes, mouth, voice – they’ll turn into this murderous, avenging Steppenwolf from the planet Apokolips, apparently. Who’s bent on Hell on Earth.
Justice League has a November 17, 2017 release directed by Zack Snyder, with the story by Chris Terrio and Zack Snyder, the screenplay by Chris Terrio and Joss Whedon, and stars Ben Affleck as Batman, Henry Cavill as Superman, Gal Gadot as Wonder Woman, Jason Momoa as Aquaman, Ezra Miller as The Flash, Ray Fisher as Cyborg, J.K. Simmons as Commissioner Gordon and Willem Dafoe an Atlantean, Nuidis Vulko.
Fueled by his restored faith in humanity and inspired by Superman’s selfless act, Bruce Wayne enlists the help of his newfound ally, Diana Prince, to face an even greater enemy. Together, Batman and Wonder Woman work quickly to find and recruit a team of metahumans to stand against this newly awakened threat. But despite the formation of this unprecedented league of heroes—Batman, Wonder Woman, Aquaman, Cyborg and The Flash—it may already be too late to save the planet from an assault of catastrophic proportions.