Brainiac and Lex Luthor's complicated history explained before Man of Tomorrow

Brainiac is the main villain in Man of Tomorrow, but Luthor could switch sides

James Gunn announced in September that he was working on Man of Tomorrow, a follow up to Superman that would see Lex Luthor (Nicholas Hoult) and Superman (David Corensweet) teaming up against a greater threat. After months of speculation, Gunn confirmed on Dec. 20 that the threat will be Brainiac, played by German actor Lars Eidinger (Babylon Berlin, All the Light We Cannot See).

In the same thread, Gunn expressed his love for many iterations of Brainiac, including the city-stealing version first created by Otto Binder in Action Comics #242 in 1958, the “surprisingly scary” robotic version created by Marv Wolfman and Gil Kane in the ‘80s, various animated versions, and the “truly creepy” Brainiac working with Ra’s al Ghul in Absolute Superman. That doesn’t provide much information on how Gunn will approach the supervillain, but we might be able to glean some information from the fact that this movie also involves Luthor.

Luthor and Brainiac have a long and complicated history. The two villains teamed up in a 1964 Superman story from Cary Bates and Edmond Hamilton filled with Silver Age silliness — they shrink the Man of Steel and hit him with a “coma-ray.” Brainiac and Luthor were part of a team involving plenty of other villains for the Crisis on Infinite Earths crossover event in the ‘80s.

The two villains have a more complicated relationship in the animated series where they’ve both appeared. In My Adventures with Superman, Lex gets his start working with Task Force X, creating an army of robots for Amanda Waller that he uses to fight off Brainiac’s invasion. In Superman: The Animated Series, Brainiac reveals that he has downloaded himself into LexCorp’s computers, captures Luthor, and forces him to build him a new robotic body. Luthor is eventually saved by Superman, working with Luthor’s loyal assistant Mercy.

That plot was continued in Justice League Unlimited, where Brainiac reveals that he also infected Luthor with nanites. The tech cures Luthor’s Kryptonite poisoning and gives him super strength, but Brainiac really just wants to use him as a temporary host he will kill when he finds a better body. Luthor convinces Brainiac to fuse with him, creating a being powerful enough to remake the universe. While the Justice League is able to separate the two, Luthor becomes obsessed with Brainiac and spends the rest of the series trying to fuse with him again. That effort eventually leads to Luthor accidentally resurrecting Darkseid, forcing him to team up with the Justice League to fix his own mistake.

But the story that might have the biggest hints of what we can expect from Man of Tomorrow is Joshua Williams’ 2024 Superman: House of Brainiac arc. That story starts with Luthor in prison when Brainiac invades. At various points of the story, Brainiac and Luthor work together to fight Superman, and later in the story, Luthor switches sides and works with Superman to fight Brainiac. Lobo and Supergirl are both big characters in the storyline, and their appearance together in Supergirl could be setting that arc up.

Luthor claims to be an advocate for humanity, but he’s primarily driven by his own ambition and ego. He might be teaming up with Superman to fight Brainiac in Man of Tomorrow, but he’ll likely be looking out for his own interests first and will turn on Superman as soon as he can.