Charles Dance, known for playing Tywin Lannister in Game of Thrones, might be up for Justice League. The info comes from a Twitter account, so this could be another rumor to take with a grain of salt.
Charles Dance might not be a bad choice for one of Darkseid's generals. If you saw the SyFy miniseries, Childhood's End, Dance played the alien leader Karellen (see below), which came off rather well, I thought.
While Steppenwolf was cut from the Batman Vs. Superman theatrical version for some odd reason, the scene does make its way into the Ultimate Edition. Zack Snyder and WB also released the deleted scene following the debut of Batman Vs. Superman in theaters. The scene goes a long way to explain why Lex acts the way he does at the end of Batman Vs. Superman and also helps set up the Justice League movie. Watch it below.
"Justice League" has a November 17, 2017 release directed by Zack Snyder starring 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, Jesse Eisenberg as Lex Luthor, J.K. Simmons as Commissioner Gordon and Willem Dafoe as an Atlantean.
Batman Vs. Superman Steppenwolf deleted scene "Communion":
Charles Dance from SyFy's Childhood's End as Karellen: