Spoilers ahead for tonight's episode of Supergirl, titled "City of Lost Children."
Bringing hundreds of ships -- thousands of aliens -- to Earth, Rhea christened the world New Daxam, signaling a move to use her super-powered army to take over the world.
Of course, as powerful as they are, the Daxamites are pretty vulnerable to lead...and given that lead is not only pretty common on Earth, but used in many of our projectile weapons...well, that makes war just as deadly for them as it would be for anybody else.
The "New Daxam" idea is hardly a new one -- although in the comics it has typically gone by "New Krypton."
We're going to limit our New Krypton observations to the storyline of the same name, published from 2008 to 2010 by DC Comics, with the caveat that the concept had existed in various forms before that. The Eradicator even tried to create a New Krypton by terraforming the planet during the "Day of the Krypton Man" storyline...
..which of course sounds familiar to fans becuase it's what General Zod attempted in Man of Steel.
One of the biggest influences on Supergirl has been the Sterling Gates/Jamal Igle run on the comic, which not only helped shape Kara Zor-El's character for a new generation (there had been a different Supergirl for quite some time), but also introduced a new Superwoman who would go on to play a major role in the series.
Gates came on board Supergirl just as Geoff Johns and James Robinson, who were then writing the Superman titles, had laid out two years' worth of story that would cross over between Superman, Action Comics, and Supergirl with more regularity than had been done in years.
The story? New Krypton.
Johns had just had massive success reinventing the character of Brainiac, restoring several elements of his backstory which had been removed in the post-Crisis on Infinite Earths era. One thing Johns had brought back was the Bottle City of Kandor, in which Brainiac had thousands of Kryptonians miniaturized and held hostage.
When Superman freed them, though, that just left thousands of Kryptonians -- not all fo them heroic -- hanging out on Earth.
That wasn't all it was cracked up to be, of course.
Superman ended up spending so much of his time dealing with jerk Kryptonians in various shapes, sizes, and fashions, that the comic became essentially Mon-El's, as he took on the Superman logo and helped out in every issue.
Meanwhile, things got increasingly heated between the Kryptonians -- who wanted sovereignty and had the power to take it if things went the wrong way -- and humans.
Things got so bad at one point that they even called in Lex Luthor -- an unpopular former President and known criminal -- to consult.
It seems as though that element is playing itself out in Supergirl, too, as Lillian Luthor looks to be not only out of jail but actively helping the authorities in the teaser for next week's episode.
Along the way, though, we did get new versions of Superwoman, as well as the Kryptonian Silver Age heroes Nightwing and Flamebird.
Once all was said and done, there was really only one place for the Kandorians...
WORLD OF NEW KRYPTON
...To the moon!
Superman took on a diplomatic role and the Kryptonians went to settle on the moon for a while, until militaristic factions led by Zod became a danger to Earth and other inhabited planets in the DC Universe.
Ultimately things went very bad, very quickly; many of the Kryptonians died, and some were rescued and taken out into space by Adam Strange's Zeta Beams.
Putting Supergirl or Mon-El in the position that Clark took -- essentially trying to keep the peace -- would be very different than having Superman do it. Superman was already a global inspiration to the people of Earth and the salvation of the Kandorians, making him an obvious candidate. His failure was, in part, due to the fact that he didn't really belong to Krypton, having been an Earthman his whole life.
Neither Mon-El nor Kara have that: both of them could easily get along with their home races...particularly Mon-El, who seemingly hasn't been gone that long.
In any event, if anything it seems this element will end up being used in the finale, when they need a way to save the Daxamites without turning them all away back into space, which would fly in the face of the refugee-supporting message of the season. And in that case, it would likely be Mon-El who has to head to space and help them resettle...!