It's no surprise that Supergirl fans are demanding to see the heroine join the DCEU movies, but for reasons they might not realize, a Supergirl cameo or introduction in Justice League makes a lot more sense than Man of Steel 2. With Wonder Woman a massive hit at the box office and on pace to potentially out-gross Superman's first film, the idea that female-led films are more of a risk has been shattered. The time has come, say the fans, for Kara Zor-El to join Diana in giving her Kryptonian cousin some competition. And just that easily, rumors of Supergirl debuting in Man of Steel 2 began to surface.

Those rumors were debunked soon after, and for good reason: sticking with the best surviving rumors going back to the Man of Steel days, a Superman sequel starring Brainiac and Supergirl is the most obvious story. But as much as we would love to see what Supergirl's DCEU costume would look like, and who could be cast in the part, there's one big problem with the idea of her crash-landing on Earth... the fact that she already did.

That's right, Zack Snyder already established Kara Zor-El in Man of Steel's history and movie franchise. And while her story may rule out a modern cameo, there's reason to hope that Supergirl is seen in Justice League... just not where you would expect.

The Kara Zor-El of The DCEU

Supergirl Comic Man of Steel Prequel

It seems like so long ago that Zack Snyder's Man of Steel was still approaching, and the new take on DC's heroes it would launch still a mystery. Before fans got their first answers with the new Superman origin story, the writers of the film filled in another hero's place in Krypton's history: Kara Zor-El, better known as 'Supergirl.' The story was told in the aptly-titled comic book MAN OF STEEL Prequel: Special Edition, beginning long before the destruction of Krypton ever loomed in the minds of Jor-El or Lara Lor-Van.

Now if you're thinking that a tie-in comic isn't meant to be taken as canon, the story itself was cooked up by Zack Snyder, David S. Goyer, and Geoff Johns (written by Sterling Gates and drawn by Jerry Ordway). Not only are those the same minds that helped create the story of Man of Steel and Batman V Superman, but Snyder and Johns remains premier shapers of the DCEU, having recently developed the story for Wonder Woman. So if their version of Kara's story was written and published, it carries an air of finality.

As a member of Krypton's Explorer's Guild, it was Kara's fate to lead one of the countless Scout Ships across the galaxy in search of new worlds. Once one was found the ship's Genesis Chamber was to be used to create an entire new host of Kryptonian citizens, as Kara and her officers blazed a trail as the founders of a new world. It's the optimistic, expansive spread of the Kryptonian Empire that an artificial intelligence of Jor-El recounts to Kal in Man of Steel (before Krypton was swallowed up by isolationist thinking and population control).

After a tragic, heartbreaking incident in final training, Kara stands ready to graduate and lead one of thousands of said Scout Ships into the stars, and receives The Star of Rao - Krypton's highest distinction. But it isn't just excellence that runs in the House of El... it's a permanent separation from their family. Where baby Kal-El was bid farewell by his parents moments before their planet's destruction, Kara leaves knowing that her mission will carry her lightyears into the cosmos. She will never see her parents again either, but they know she is bound for great things (it's a nice parallel to Man of Steel).

If you're wondering: "does Kara's mission lead to horrible sabotage and tragedy?" the answer is an emphatic 'yes.'

'Supergirl's Arrival on Earth Ends in Disaster

That tragic incident in final training that we mentioned before was the death of Kara's love, a fellow Explorer named Kell-Ur. It was Kara who discovered Kell just as he fell to his death, eventually realizing that he had been murdered by another member of their team, named Dev-Em. Killing Kell in order to make his odds of being among the final graduates, he is ultimately defeated and subdued by Kara, and found guilty of murder - the first Kryptonian murder in 1,000 years. Unfortunately, Kara's mission into the stars doesn't put Dev-Em behind her.

Apparently, some of Krypton's leaders still stand against the death penalty, and help secret Dev-Em away to isolation and essential exile aboard a Scout Ship... Kara's Scout Ship. Kara is horrified to awaken from her cryo-sleep to find the other pods empty, and her intended crew reduced to skeletons. Dev-Em had woken them up one by one, spending a decade as leader of the ship - leaving Kara for last, and his intended bride on their future planet. A planet that, thanks to Dev-Em, is no longer their intended target. For reasons known only to him, Dev-Em has selected Earth as their destination.

The pair return to their battle, confused to find that they are suddenly strong enough to punch though the material of the ship (a byproduct of Sol's yellow radiation). Kara again subdues Dev-Em as she takes her Captain's Chair to try to salvage the ship from the damage they have inflicted upon it. But it's all futile, and with thunderous explosions, the ship slams into Earth - making Kara Zor-El the first Kryptonian visitor to its surface, not her cousin Kal. An accident that would change the planet's fate forever...

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Kara Zor-El's Crashed Ship Becomes Superman's Fortress

Since the comic was published prior to Man of Steel even releasing, those fans who read it could be forgiven for missing some of the obvious connections. For starters, the image of Kara's Scout Ship burying itself into the snow of Earth's frozen north - and being slowly layered over with more snow, and more snow, until it's almost entirely concealed - could be missed. But the diehard Man of Steel fans see the connection being made before their eyes: Kara's crashed ship (which begins self-repairs as it crashes) is the same one Clark Kent discovers as his DCEU Fortress of Solitude.

To make the entire twist even more twist-y, the comic shows a single figure exiting the crashed ship and disappearing into the distance. It doesn't specify whether the figure is Kara or Dev-Em, and fans can speculate on their odds of survival (Dev's injuries were far from lethal, and Kara was alive behind the controls at the point of impact. But regardless of who survived and who didn't such an historic event is hard to miss by the people who live nearby - even in the remote North of Canada.

The images that close out the story show the Scout Ship almost entirely buried in ice and snow as a group of Inuit people hunt nearby. When they make their catch, they return to their home... a home decorated with art of the crashing Scout Ship in flames, and Kara's famous 'S' sigil of the house of El. Her arrival made history in the region... which is where things get really interesting for Justice League and the past and present of the DCEU.

Supergirl Arrived Before Justice League's Ancient Prologue

Justice League Trailer War Prologue

It's a thrilling story regardless of whether or not Kara Zor-El's life continued beyond the crash, but what matters more than what she accomplished is when she accomplished it. As Jor-El explains to Kal in Man of Steel, the Kryptonian 'Age of Expansion' that saw Explorers like Kara sent into the stars took place thousands of years in Krypton's past. Likewise, Man of Steel's American scientists are puzzled to find a signal being emitted from the Scout Ship when the ice surrounding it is "almost twenty thousand years old." The dates add up, with Kara Zor-El living and dying (Kryptonians aren't immortal... we don't think) thousands of years in the past.

That alone means that a cameo, introduction, or full story in the modern DCEU is almost impossible. But what it means for Justice League's opening battle against Apokolips is another story. The filmmakers have yet to pin down an exact date for this battle, saying only that it took place 'thousands of years ago' in Earth's history. A more specific date might not be all that helpful, since it's clear from the people fighting the battle that Earth's own history and prehistory are not the template being used.

Aside from the humans wearing iron armor and animal pelts, the forces of Apokolips are up against a younger, wilder group of Amazons led by Hippolyta and Antiope, and the already-glorious empire of Atlantis... before it was sunk beneath the ocean.

Justice League Trailers Amazons

 With the accompanying Man of Steel prequel comic and now this Justice League prologue and Mother Box intrigue, the early history of the DCEU's Earth is getting more and more interesting. So where does Supergirl, or Kara Zor-El fit in? Surely a woman arriving from the stars, and possessing the powers of Superman would be noticed in a history filled with not one, but three growing empires. So why is it that Superman's famous symbol hasn't been recognized as the same one belonging to - what appears to be - Earth's first true superhero?

More importantly, why doesn't the world know more about Kara Zor-El's arrival? Is it more likely that Snyder, Goyer, and Johns came up with a new version of Supergirl for kicks, or as part of some larger story or DCEU mythology? We're inclined to think the latter, and if that's the case, then the Justice League prologue holds the most promise for some confirmation. The modern world of the DCEU has forgotten the Amazons, Atlantis, and even the invasion of Apokolips they helped stop. When Justice League begins, fans will get to look thousands of years into the past - to a time when Kara Zor-El's life was relatively recent.

That alone should let fans spin some exciting theories of their own. If Kara Zor-El lived to become the same type of hero as DC's Supergirl, was she mistaken as a mythic god like Hercules? Do the Atlanteans owe their unique physiology and grand, refined, alien-like armor and architecture to the surviving Kryptonian? Was Kara's Genesis Chamber put to use before she abandoned the Scout Ship? Was her arrival on Earth part of the reason Darkseid and Apokolips took notice of it at all? We have only questions, and the imagination to answer them until answers are given.

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It's no doubt disappointing to Supergirl fans to see that the DCEU's take on Kara Zor-El took place in the past, but it's possible a new Kara could also be born (which would make the prequel comic a lot less interesting). The bottom line is that at this point, we know when Supergirl came to Earth. And if fans are looking for answers, Justice League's opening battle may be the closest we ever get to witnessing the impact she had on the planet her relative would call home thousands of years in the future.

NEXT: Supergirl in Man of Steel 2 Rumor Debunked?

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