'Supergirl' may use Lex Luthor's resurrection in season 5 to set up new Legion of Doom ahead of 'Crisis on Infinite Earths'
Versions of many Legion members from the comics like Gorilla Grodd and Brainiac have already been introduced into the Arrowverse. Brainiac 5, the heroic future version of the classic Superman villain, is already part of ‘Supergirl’
Lena Luthor (Katie McGrath) may have fatally shot her evil brother Lex Luthor (Jon Cryer) at the end of ‘Supergirl’ season 4 but the criminal mastermind is far from done. The last moments of the finale showed Mar Novu the Monitor (LaMonica Garret) taking Lex’s corpse for purposes unknown, hinting he will likely be returning from the dead in season 5.
Lex’s survival could mean ‘Supergirl’ might be preparing to introduce a new version of the Legion of Doom. In the comics, the Legion is an elite group of the universe’s worst villains specifically handpicked by Lex himself.
The second season of 'The Flash' spin-off series 'Legends of Tomorrow' had Damien Darhk (Neal McDonough) and Malcolm Merlyn (John Barrowman) from 'Arrow' teaming up with Matt Letscher's Eobard Thawne to form a version of the Legion. Though that team-up eventually fell apart, the Legion of Doom plays an important part in the comics version of the 'Crisis on Infinite Earths' so bringing them back makes sense.
Versions of many Legion members from the comics, like Gorilla Grodd and Brainiac have already been introduced into the Arrowverse. Brainiac 5, the heroic future version of the classic Superman villain, is already part of ‘Supergirl’.
In season 4, Brainiac aka "Brainy" (played by Jesse Rath) had his mind rebooted leading to the return of his ancestor’s villainous tendencies, though they seem to be under control right now. If he were to break bad, Brainiac 5 could cause untold devastation using his prodigious intellect.
Considering Brainy has just started a relationship with Nicole Maines' Nia Nal, having him become a villain would be truly heartbreaking. Of course, if the Monitor is responsible for bringing the Legion together, they may be a force for good and useful allies against Mar Novu's evil twin the Anti-Monitor.
Unfortunately, there is also the chance the Monitor may not be the force for good he appears to be. If it should be revealed that the Monitor we know is actually the Anti-Monitor, the Legion of Doom will be the primary army for the side of evil.
To be fair, the Monitor has done quite a few questionable things so far, including bringing Phil LaMarr's Malefic, the evil brother of the Martian Manhunter (David Harewood), to the world of 'Supergirl'. DC's ongoing 'Justice League' comic book series has introduced a new, deadlier version of Luthor who has absorbed the Manhunter and transcended his human form to become an Apex Predator.
While Malefic could become a useful ally for Luthor and a particularly useful member for the Legion, Lex may yet attempt to use the villain as a tool for his own ascension. Whatever the Monitor's plans for Lex may be, it won't be long before the villain tries to complete his vendetta against Kryptonians again. With all the threats Melissa Benoist's Kara Danvers/Supergirl will have to deal with in season 5, the formation of the Legion might just spell her doom.
'Supergirl' season 5 will begin airing on The CW October 6.