Supergirl is one of DC’s most powerful and storied heroines, but her spectacular career was put on hold after she was exposed to Gold Kryptonite, which permanently robbed her of her powers. In her stead, there has to be a new person to step up to the plate and take on the burdens of being Supergirl, and thankfully, there are plenty of options in her newly formed team, Super-Force. It brings together heroines both new and old, including Matrix, who once served as Supergirl in the post-Crisis continuity, before Kara was reintroduced. However, she’s not the strange Supergirl in question. Neither is, surprisingly enough, Kara’s dark half, Nightflame.
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No, the Supergirl who took over the mantle is none other than Thundergirl. If you don’t know who she is, that’s because she’s a recent addition, having just been introduced during the “Reign of the Superboys” storyline. However, while Supergirl (2025) #19 showed us that Thundergirl is the perfect character to carry the mantle while Kara is out of commission, that doesn’t make her sprint to this status any less strange. That’s because Thundergirl has one of the strangest origins out of any superhero, which includes being inherently tied to the legendary Kingdom Come because she’s a clone of one of the most underrated villains/anti-heroes of all, Mangog.
An Origin that Connects Decades of Lore
Image Courtesy of DC Comics
Before we dive into how Thundergirl will serve as the temporary new Supergirl, let’s go over exactly who she is. She debuted in Supergirl #11, being one of the several clones created by Kim-Da, a scientist from the Bottle City of Kandor. He mixed his DNA with the genetic genome of Boy Thunder, who once served as Superman’s sidekick when he was rocketed to the main DC Earth from another dying world in the multiverse. Thundergirl was the first clone made, and the combination of the young David and Kim-Da’s DNA created a unique combo of powers. Thundergirl developed some limited Kryptonian powers, such as flight, as well as a sonic scream, which serves as her main attack. Eventually, she chose to leave Kandor and work alongside Supergirl as a hero.
Of course, just being a clone is commonplace enough, right? Wrong. See, Boy Thunder wasn’t simply a random child from the multiverse. After a brief period serving as Superman’s first sidekick and surrogate son, the same energy that brought him to Earth took him to another world, where he met the mighty and near all-powerful Old God, Gog. David became Gog’s champion and was sent as his disciple to Earth-22, otherwise known as the world of Kingdom Come. There, David grew into the hero Thunderman, and eventually Magog. He would go on to kill the Joker, stealing Metropolis’s faith and killing Superman’s, and was even involved in the nuclear explosion of Captain Atom that wiped out Kansas.
So, to recap, Magog was the leader of the anti-heroes in Kingdom Come, embodying the trend of morally grey killers claiming to be superheroes that the story was created to critique in the first place. He briefly served as Superman’s sidekick and surrogate son, during which he met with the scientists of Kandor. Then, years later, Kim-Da decided to make clones of this random child whom he met perhaps once, and while most of the clones would degenerate, Thundergirl would rise above them as the sole survivor and go on to join Supergirl’s friend. And she, frankly, was just introduced to reference Boy Thunder in the “Reign of the Superboys” event, but her character is being run with. This is an origin so convoluted it stretches across decades, and I love it. It shows exactly how wild comic book origins can be, and also gives us a good guess about what Thundergirl’s time as Supergirl could look like.
A New Supergirl, Potentially from a Bygone Age
Image Courtesy of DC Comics
After Kara left her powers, the rest of Super-Force immediately debated over who should inherit the cape, which led to an all-out brawl between those who supported Matrix and those who supported Nightflame. In the end, Thundergirl convinced everyone to stand down, being the only super-powered heroine to keep her cool. That inspired Kara to offer the position to her, as Supergirl had to be a symbol for ultimate good, but while she might have gotten the job for keeping her emotions in check, we don’t know how long that’ll hold. After all, Thundergirl doesn’t even have her own name yet, using her time as Supergirl as a chance to develop her own identity.
That’s where the danger lies. She’s a clone of David, whose emotional instability cost literally millions of lives, meaning that she at least has the potential for that kind of darkness inside of her. The real truth, however, is that David’s anger came from fear of losing what he had and cowardice. Thundergirl has not shown signs of this, yet, but imagine if she starts to see being Supergirl as something that gives her purpose and a place in the world. She’s a woman struggling to find how and where she belongs, and Supergirl is the path to that. When Kara inevitably gets her powers back, a fight between them would more than make sense. Thundergirl barely has any experience in the world, and who would someone rather be than Supergirl?
What do you think is going to go down with the new Supergirl? Let us know in the comments below!
Supergirl #19 is on sale now!
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