'Batman v Superman' hints at an epic villain for the future 'Justice League' movie

Warning: There are spoilers ahead for "Batman v Superman." The first screenings of "Batman v Superman" have finished and it is a lot to process.  While the main villains of the film are Doomsday and Lex Luthor, the film hints at a larger force down the line that DC's finest may have to combat. We've seen it teased in one of the film's previous trailers here. Last chance to head back before spoilers! Warner Bros. In one of the film's best -- and maybe most confusing -- sequences, Bruce Wayne...