Krys Marshall makes her Supergirl TV show debut as the deadly Worldkiller Purity in a new image.

Supergirl season 3 has seen the Girl of Steel facing off against the terrifying threat of Reign. The latest episode, 'Legion of Super-Heroes', featured the eagerly-anticipated rematch between Kara and Reign. This time round, Supergirl triumphed with the help of the Legion and an injection of Kryptonite. Unfortunately for Supergirl, the episode ended with Reign learning there are other Worldkillers on Earth.

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In an exclusive photo released to EW (see below), The CW have revealed that Kara will soon find herself battling a second Worldkiller. This character goes by the name of Purity. She's played by Krys Marshall, and will make her debut on the show's February 5 episode - the final episode before Supergirl goes on hiatus, with Legends of Tomorrow taking over its timeslot for nine weeks. No doubt the battle with Purity will be a key moment in the series, although Supergirl showrunners Jessica Queller and Robert Rovner teased that their showdown will be "full of surprises."

In the comics, five Worldkillers survived the destruction of Krypton. Reign was their leader, and it's a safe bet that will be true in Supergirl too. The Worldkillers of Supergirl appear to have taken on symbolic identities; Purity, for example, is a clear nod to the Worldkillers' stated goal of destroying everything they judge to be "sin." By that measure, Reign's name clearly identifies her as their leader, their queen. Supergirl and her allies can only hope the other Worldkillers aren't as powerful as Reign, but this first photo doesn't look promising. Purity certainly appears to be able to take Supergirl on one-on-one.

In the Supergirl mythology, the Worldkillers survived Krypton's destruction, and have lain dormant for years. Each Worldkiller has grown up believing they were an ordinary human. In the case of Reign, her human persona - Samantha Arias - is actually a close friend of Kara Danvers'. Most importantly, she also has a daughter, and her love for her daughter seems to be a more powerful force than any Kryptonian science. That could easily turn into her greatest weakness, and could even lead to a redemption arc for Reign. Notice that this teaser image doesn't show Purity in anything resembling a costume. It looks as though Kara wasn't aware she was dealing with a Worldkiller; instead, she turned her back on what she thought to be an ordinary human. This encounter could easily clue Supergirl and her allies in to the truth, that the Worldkillers have secret identities too.

Can Supergirl actually defeat two Worldkillers? And if there are two, could there be five, as in the comics? If that's the case, even the help of the Legion of Super-Heroes may not be enough to stop these rogue Kryptonians.

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Supergirl continues tonight, January 22 with ‘Fort Rozz’ on The CW.

Source: EW