The CW's Supergirl ended its midseason finale on a truly devastating note. Kara finally went head-to-head with season 3's big bad Reign, the Worldkiller, and the confrontation left the heroine completely wrecked. In the battle, Reign proved to be superior when she pummelled Supergirl to a pulp, leaving her a bloodied mess smashed into the pavement. Kara barely made it out alive - she was only saved thanks to the efforts of the DEO, and she was left in a coma at the end of the episode.

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In on fell swoop, Reign was established as the worst and most dangerous villain the show has seen yet, while cementing herself as a true force to be reckoned with for the remainder of the season. When Supergirl returns from its winter hiatus, the series will need a clear endgame to propel the start of the second half of the season, and it just so happens that it could look to "Reign of the Supermen," a very famous Superman comic book storyline for inspiration -- even if in name only.

"Reign of the Supermen" was a 1993 storyline that took over most of the Superman comic book titles after Clark Kent had fallen at the hands of Doomsday. While the Man of Steel had very famously died, he would eventually return later on. But in his absence, the DC Universe saw four Superman-related characters step up to try and fill the void that the character had left, each declaring themselves the one true Last Son of Krypton.

In Supergirl, Kara might not have died, but she was certainly left for dead by an enemy who is clearly more than her match. The promo for the next episode have confirmed that the character will still be in a coma when the show returns, meaning that this could create a vacuum that some characters could try to fill. With Supergirl down for the count, Reign could surely step up, presenting herself as the true savior of this world -- something she was already bred for. And besides, "Reign" is right there in her name, which would make the comic book storyline even more perfect for the rest of the season.

But that's not all. The Superman comics explored the idea of multiple Supermen. On Supergirl, we have already seen quite a few female superpowered characters that could be brought back to live up to the "Superwomen" part of the idea. In fact, Bizarro-Girl was already introduced all the way back in the first season of the show. Her return would make for a nice touch, and she could once again be explored as both an enemy and a possible ally in the events to come.

There is also a chance that we could witness the rise of Miss Martian. With her shape-shifting abilities, she could give herself the appearance of a Kryptonian so as not to make the residents of Earth nervous with her Green or White Martian forms. M'Gann could just appear as her human self, with her Martian costume. With her powers of strength, flight and laser vision, she could easily pass for a Supergirl replacement.

Then, there is the little fact that we very recently met one of Kara Danvers' evil doppelgangers. In the Arrowverse crossover event "Crisis on Earth-X", we met Overgirl, the evil nazi version of Supergirl from an alternate Earth. While Overgirl didn't make it out of the crossover event alive, we did get confirmation, courtesy of Harrison Wells, that there are 53 Earths in the multiverse, and 53 Karas. While Wells could have named any other superhero, it could be that it wasn't for nothing that the writers had him mention that there were 53 versions of Kara out there. Perhaps others will manifest themselves. Perhaps even Overgirl could return, having survived the solar detonation that we thought had killed her.

"Reign of the Supermen" had four characters declaring themselves the one true Superman, and one of them was entirely new at the time: John Henry Irons, aka Steel, a character who would become part of Supergirl's comic book cast for a time. Could Supergirl also use this storyline to introduce Steel in their universe, or someone to fill in that role? Such an undertaking could be the perfect springboard to introduce a new character on the series.

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It seems that the pieces are all but set for Supergirl to launch its very own take on the popular comic book storyline, but whether the series will actually go there or not remains to be seen. On television, "Reign of the Superwomen" could easily tie into the big bad of the season, while bringing back some old fan-favorites and maybe even introducing some new ones. Until Kara returns ready to fight again, National City could see its own rise of superpowered female characters, leading to what would surely be an epic and fiery finale. A true clash of Superwomen.