
James Gunn's DCU is about to kick off, starting a new beginning for DC Comics' on-screen endeavors. While right now, the Guardians of the Galaxy filmmaker is keeping things relatively small, he will need to get big eventually, giving his super-powered Gods & Monsters phase of storytelling a Thanos-like, ever-present villain to bring its characters together.
It is unclear how long the DCU's first phase will run or how many projects it will consist of, but it is more likely that it is leading to something, with some speculating that the formation of the Justice League could be that Phase One culmination point.
If Gunn is going to bring together characters like Superman, Batman, and Wonder Woman on-screen, he will need a threat worthy of these heroes banding together rather than taking it alone (like Thanos did in the MCU). Thankfully, DC Comics has plenty of Justice League-worthy threats that could work perfectly on the big screen.
6 Villains That Could Be the Perfect DCU Answer to Thanos
Lex Luthor

The most obvious (and probably most likely) answer to this DCU Phase One Thanos problem is Lex Luthor. Luthor is a megalomaniacal supergenius who hates nothing more than Metahumans getting the spotlight when he (an everyday man) thinks he deserves all that attention.
Luthor makes sense as the Gods & Monsters big bad as he is already cast in the DCU and will play a big part in its first movie, Superman. Former X-Men: First Class star Nicholas Hoult will play the character in James Gunn's DCU kick-off movie, introducing audiences to this new take on the character.
It would be a shock to see Lex defeated and tossed away after a single movie in the super-powered franchise. So, perhaps he will come back with a vengeance later in the series, serving as the big bad for the greater DCU Phase One story. Maybe he will bring friends next time, assembling the evil Legion of Doom (a group of supervillains assembled by Lex in the comics to combat the Justice League).
Darkseid

Darkseid is about as close to Thanos (in both look and narrative purpose) as it gets in DC. The character was last seen in Zack Snyder's DCEU, serving as the culminating villain in that story as well.
Darkseid is an all-powerful, God-like figure known for being the tyrannical ruler of the planet Apokolips. Like Thanos, he has a universe-spanning end goal, although his is more unquestionably evil. His plan involves harnessing the Anti-Life Equation to enslave the DC Multiverse and rid all realities of hope and free will.
Introducing Darkseid this early on might seem like a bit high-stakes at this point, but perhaps he could play a similar role to the DCU's first chapter that Thanos did to the MCU Phase One. Maybe another villain will serve as the primary initial threat, only to be revealed to have been working for Darkseid the whole time, setting up his appearance somewhere down the line.
Doomsday

Doomsday is one of the most iconic DC villains ever, making him a candidate for this DCU big bad role.
Doomsday is probably best known in the comics as the monster responsible for killing Superman. He is a genetically engineered Kryptonian monster, imbued with hate and a desire for destruction. Doomsday previously appeared in the DCEU and would likely only appear in James Gunn's reboot if he were to kill Superman.
Bringing him in early and making him a threat for the entire early Justice League could be an interesting move for the DCU, setting him up as an ever-present threat before eventually doing the whole Death and Return of Superman thing in several Phases later.
Krona

A big-name DC Comics villain who has not yet been given the theatrical treatment is the terrifying Krona (as seen in the animated Green Lantern: Emerald Knights). The character has been a staple of Justice League and DC stories, essentially serving as the catalyst for creating the DC Multiverse in the comic books.
The character is an alien scientist from the planet Krona who is hell-bent on discovering the origins of the known universe. Even though he knows that uncovering this secret will bring about a massive universe-spanning calamity, Krona presses on, developing a machine to help him that accidentally breaches the bounds of reality and creates the DC Multiverse.
With no indication that the Multiverse will be present in the DCU as of yet, bringing in Krona as an ever-present threat could be a way for James Gunn to slowly introduce the idea of alternate realities by giving his DC heroes a villain who has an active hand in creating them.
Parallax

While many of the villains on this list have a clear connection to Superman (which would make sense given how Superman is the first film in the DCU), there is another corner of the DC universe that James Gunn's new universe will tackle in its first couple of years... The Green Lanterns.
Because of this, introducing someone like Parallax as the overarching villain for the Gods & Monsters story makes sense. Parallax is the star-faring power source of the Sinestro Corps, serving as one of the Lantern's most formidable foes.
With Adam's Apple actor Ulrich Thomsen set to appear as Sinestro in Lanterns, bringing in the thing that powers the character's evil energy as a big bad could be the perfect chance to lean into the intergalactic side of the DC story and build on the foundation set up by the upcoming HBO superhero series.
Brainiac

Another iconic DC Comics villain (and one of Superman's most iconic comic book foes) is the dastardly Brainiac. The super genius technoorganism has long gone up against DC's best and brightest, serving as a key antagonist in several significant DC Comics stories.
The character is an android from the planet Colu on a quest to collect all knowledge in the known universe. As a part of this crusade, he keeps the planets, places, and things he conquers as trophies in small glass domes strewn about his spaceship. As one can expect, the heroes of the DC world take issue with this pursuit, especially when it has anything to do with Earth.
Some have wondered if Brainiac could be a secret villain hidden in James Gunn's Superman, potentially setting him up as the next big bad for the Man of Steel (and potentially others) to take on in the DCU.