Warning: The following feature contains SPOILERS for Crisis on Infinite Earths.
While the Arrowverse crossover event Crisis on Infinite Earths brought big changes to all of The CW's superhero shows, Supergirl was perhaps the most drastically changed of all. This was probably inevitable, given how Kara Zor-El and her friends and family arguably lost the most out of everyone involved in the battle to save all reality.
The first chapter of Crisis on Infinite Earths saw Supergirl and her allies wage a losing battle to protect Earth-38 from an all-consuming wave of anti-matter sent forth by the Anti-Monitor. Eventually the heroes' battle became one of attrition, fighting only to buy time for more civilians to be evacuated through the combined efforts of Lena Luthor and an armada of alien ships assembled by Martian Manhunter. A little under half the population of Earth-38 survived, with Green Arrow sacrificing his life to save one billion people from annihilation.
Sadly, the effort seemed fruitless after all of the multiverse fell to the Anti-Monitor, save for seven Paragons; great heroes prophecy claimed held the key to saving all that existed. Supergirl was among these Paragons and together they were able to forge a new universe. But just as in the original Crisis on Infinite Earths comics, there were many things in this new reality that were as different as they were familiar. Here is a run-down of everything that will make Supergirl an entirely different show post-Crisis.
Lex Luthor Is Alive
Of all the many surprises Supergirl had to deal with during Crisis on Infinite Earths, the resurrection of Lex Luthor was the most unpleasant. Luthor had died during Supergirl's season 4 finale, shot through the chest by his sister, Lena, after faking his death in an explosion while battling Supergirl. Lex had his revenge, however, using his last minute on Earth to reveal to Lena how her best friend, Kara Danvers, was secretly Supergirl and that everyone Lena had come to value as a friend shared that secret and agreed to keep Lena in the dark.
To Supergirl's annoyance, the Monitor had brought Lex back from the dead, saying that his intellect would be needed to save the multiverse. This ultimately proved to be true, as it was Lex's scheming and his theft of a page from the reality-changing Book of Destiny that gave the Paragons the tool they needed to rebuild the universe during their battle with the Anti-Monitor. With Lex among the seven beings whose thoughts shaped the new Arrowverse, it is no wonder that his death didn't stick.
Lex Luthor Is A Beloved Hero To The Public
As "Crisis on Infinite Earths - Part 5" opened, Supergirl woke up to find herself in her apartment and late for an assignment covering the Noble Peace Prize ceremony as Kara Danvers. She was stunned to learn that the award was being given to Lex Luthor. She was further shocked to learn that her co-worker Nia Nal (aka Dreamer) honestly admired Luthor and remembered nothing about the battles they had fought together against the criminal genius and his henchmen in the previous year. Even the usually cynical Alex Danvers responded that Lex was "the best guy" when Supergirl said she couldn't believe everyone thought Luthor was a good guy.
Lex Luthor is Supergirl's Boss
Supergirl's shock at how Lex Luthor's past crimes had been forgotten by the world turned to horror when Alex referred to him as their boss. It was then that she noticed that the DEO seal on the floor of their headquarters was different, with the bottom of the emblem now proudly reading "A Luthorcorp Subsidiary." Thankfully, Martian Manhunter arrived at that moment and assured Supergirl that she wasn't going crazy and that the battle with the Anti-Monitor did occur, but only the Paragons seemed to remember that Earth-38 had been destroyed. Beyond that, he could only guess what else might have changed when their world was reborn.
While the episode didn't discuss how the DEO was run under Luthor's control, this doesn't bode well for the Arrowverse in general and Supergirl in specific. The DEO's original mission was to hunt and kill aliens on Earth, regardless of whether or not they were dangerous. Under the leadership of J'onn J'onzz and Alex Danvers, the agency became more focused on containing alien criminals and metahumans and confiscating dangerous alien technology and substances. Whatever their mission is now, with the DEO having access to the largest stockpile of alien weaponry on Earth and the ability to access information on any alien on Earth, there's multiple reasons why Supergirl would be uncomfortable with calling Lex Luthor "boss."
Supergirl Exists On The Same Earth As Other Arrowverse Heroes
A report of trouble at National City's docks gave Supergirl just the excuse she need to vent her frustrations by punching someone who deserved it. The unlucky someone turned out to be Weather Witch; a costumed criminal who seemed to recognize Supergirl, but whom Kara couldn't recall encountering. Sadly, before Supergirl could get some much needed kinetic therapy, The Flash ran in and sent Weather Witch flying with a single punch.
Barry Allen was quick to apologize, explaining that Weather Witch was one of his regular foes. A confused Supergirl asked The Flash what he was doing on her Earth. An equally perplexed Flash asked the same question, having thought they were on Earth-1. The truth became apparent as a man named Marv asked them for an autograph and said it wasn't at all uncommon for The Flash and Supergirl to team-up to fight a supervillain; Earth-1 and Earth-38 had been merged together in the reborn universe.
In short order, Barry and Kara tracked down the rest of their "super friends." With Martian Manhunter's telepathic help, they were able to restore everyone else's memories of the multiverse that had existed before. The reunion which followed proved to be well-timed, as Team Flash, Team Arrow, Supergirl, Batwoman and the Legends teamed up to fight a giant Beebo doll and a bank-robbing wizard known as Sargon the Sorcerer.
With Supergirl now sharing the same Earth as the rest of the Arrowverse shows, it will be far easier for such team-ups to occur in the future. It is unclear, however, just how frequent these team-ups might be. Team-ups are in the cards, however, with Supergirl being scheduled to appear in Gotham City at some point in the second half of Batwoman season 1.
Supergirl Is Part Of The Justice League
Another sign that Supergirl will be teaming up with her fellow heroes more frequently came at the end of "Crisis on Infinite Earths - Part 5." After attending a memorial ceremony for Oliver Queen, which The Flash had arranged to hold at the STAR Labs hangar where the heroes of two Earths first gathered to fight the invasion of The Dominators, Barry Allen revealed another way he hoped they might honor the legacy of Green Arrow. The Flash suggested they use the hangar as a base of operations whenever there was some disaster that required the World's Finest heroes join forces. He then unveiled a round table with eight chairs - one for each of the seven heroes assembled, with an empty chair emblazoned with the Green Arrow insignia.
While no name was given for what this organization should be called and no name was given to their new base, it was clear to fans of classic DC Comics' animation just what Barry Allen was up to. The new team was clearly meant to be the Justice League. And the final shot of the episode, which revealed the hangar's exterior, showed that it looked just like the Hall of Justice from the Superfriends cartoons.
Lena Luthor Still Remembers Earth-38
One question stood out among all others among Supergirl fans immediately following the conclusion of Crisis on Infinite Earths; how has Lena Luthor changed in the reborn reality? Answers came in the trailer for the second half of Supergirl season 5, which revealed that Lena still remembers her life on Earth-38 and how she killed Lex Luthor. Despite this, Lex is still running their family's company, which once again has the name LuthorCorp instead of L-Corp.
It's anyone's guess where Lena's loyalties may ultimately fall before the end of Supergirl season 5. She has no reason to trust Supergirl and her friends and Lex is a master manipulator. On the other hand, there's only one person who Lena has ever considered more untrustworthy and more dangerous than Supergirl; Lex Luthor.
Lois and Clark Have Two Sons Now
There is one major change that came about because of Crisis on Infinite Earths in the Arrowverse, which seems poised to change things for Superman and Lois Lane in their upcoming spin-off series. Near the end of the episode, Superman called Lois only to be informed that he needed to get back to Metropolis quickly because of "the boys." When Clark inquired about the plural word, Lois confirmed that she meant their sons.
In the original Arrowverse, Lois and Clark had just had their first child, Jonathan. Amusingly, Clark voiced a desire to have two sons in Supergirl, season 5, episode 9, "Crisis on Infinite Earths - Part One." It was a suggestion that Lois, perhaps still recovering from having given birth, shot down immediately. It would seem, however, that destiny had other ideas.