[Potential SPOILERS for Batman V Superman ahead.]
If heroes are only as good as their enemies, then one look at the DC Comics universe's villain gallery eliminates all doubt that their heroes are the stuff of legend. That large pool of worthwhile antagonists for Warner Bros. to choose from has only led to rampant speculation as to who the primary villains will be in upcoming DC movies like Batman V Superman: Dawn of Justice, Justice League - Part 1, and Man of Steel 2.
We've offered out pick of several different great Justice League movie villain candidates in the past, for consideration until an antagonist for the film (which Batman V Superman helmsman Zack Snyder will direct) is officially announced. One of those candidates is now strongly rumored to be the villain who will face off with Kal-El (Henry Cavill), Bruce Wayne (Ben Affleck), Diana Prince (Gal Gadot), and more, when they unite for the first Justice League feature film.
Birth.Movies.Death's Devin Faraci has commented on the most recent batch of Heroic Hollywood DC movie rumors - specifically, that Brainiac will be the Man of Steel 2 villain. Here is what Faraci had to say, regarding the report from HH's "El Mayimbe":
I trust El Mayimbe's sources, but I suspect that a lot of this stuff is scrapped now, especially as every whisper I hear about Justice League contains the word 'Brainiac.' I suspect elements of this story were cannibalized for the eventual team-up as well as BvS, whose main physical threat is, I believe, a cross between traditional Bizarro and another well-known Superman villain**...
Most comic book fans know Brainiac is a rogue A.I with twelfth level intelligence, making him one of -- if not the -- smartest beings in the universe. He possesses numerous imposing abilities including -- but not limited to -- telekinesis, and protective force fields, as well as control over technology, including computers. In most of his portrayals, Brainiac moves from planet to planet, assimilating, capturing, or simply destroying entire civilizations. In short, he would be a fitting opponent for the Justice League in their movie (hence, he made our list of great villain candidates).
As for Faraci's comment about the Batman V Superman villain, he once against reiterated the long-standing rumor that it's Doomsday, as Lex Luthor (Jesse Eisenberg) creates from the corpse of General Zod (Michael Shannon). Shannon recently back-tracked on comments that he made - suggesting that the deceased Zod undergoes a transformation when resurrected in Batman V Superman - but in truth the BvS Doomsday rumors were going strong well before the actor had said anything on the subject.
Lex Luthor and Brainiac have a long history together in the DC Comics universe, so it would be fitting if the seeds of their relationship ended up being planted in Batman V Superman, a year and a half (or so) before Justice League - Part 1 is scheduled to arrive on the scene. Furthermore, making Brainiac the first Justice League villain -- as opposed to Man of Steel 2 -- makes sense for the DC Extended Universe at large. He's undoubtedly a big enough threat to require the entire team, and sets DC apart from their competitors like Marvel's The Avengers (who face a very different in Loki, during their first time together).
Marvel Studios has done quite a bit of legwork to establish Thanos as the big bad of their cinematic universe (ahead of his showdown with Earth's Mightiest in Avengers: Infinity War - Part 1 & 2), so that puts the pressure on DC to start building its own major villains throughout the films that will build up to the Justice League movies. Brainiac also (arguably) makes more sense as the first JL foe than, say, Darkseid, given the numerous similar traits between the latter and Thanos, for example. It's something to speculate about for the time being, anyway.
Batman V Superman: Dawn of Justice opens on March 25th, 2016; Suicide Squad on August 5th, 2016; Wonder Woman on June 23rd, 2017; Justice League on November 17th, 2017; The Flash on March 23rd, 2018; Aquaman on July 27th, 2018; Shazam on April 5th, 2019; Justice League 2 on June 14th, 2019; Cyborg on April 3rd, 2020; Green Lantern Corps on June 19th, 2020. Untitled Batman and Superman solo films will be coming at dates TBD.