'Supergirl' Season 3 Predictions SPOILERS: Reign Set As Kara Danvers New Kryptonian Enemy, Who Will Play DC Villainess?

The final episode of "Supergirl" Season 2 had plenty of action as well as the tearful departure of Mon El. However, "Nevertheless, She Persisted" also concluded with a shocking flashback right before the destruction of Krypton where a mysterious group sent a baby to "reign" on Earth. The scene immediately had comic book fans wondering if this meant that a very particular villain will be making an appearance in "Supergirl" Season 3. Will DC baddie Reign find Kara Danvers when the series returns to The CW? More importantly, who will play the Worldkiller in the third season?

First of all, who is Reign? There are only a few villains that have faced Kara Zor-El, but the bizarre-looking alien has proven to be one of the most dangerous. Reign was introduced in Supergirl's New 52 reboot and was the first baddie Kara faced when she ended up on Earth. Interestingly, the Worldkiller is one of four that were created by Kara's father, who immediately regretted taking part in the project. After all, she ended up becoming one of his daughter's most dangerous opponents. But is it certain that Reign will be the new baddie in "Supergirl" Season 3?

So, Season 3 of @TheCWSupergirl will introduce #Reign as the main villain.#Supergirl pic.twitter.com/oykMphYf6b

— Comic Book Lovers (@twt_comics) May 23, 2017

In the last moments of the "Supergirl" Season 2 finale, every hint pointed at Reign's possible appearance in the series. The mysterious cloaked figure in Krypton had used blood to baptize the baby, possibly because that's what is required to create a Worldkiller, as per io9. In addition to that, the group had an interesting choice of words before they sent the infant away, stating that "it will reign" on Earth. Reign might already be close to National City and is already preparing to do what she does best in "Supergirl" Season 3. But who will portray Kara Danvers' new opponent in the CW series?

Casting for "Supergirl" Season 3 is reportedly underway and the show is already looking for an actress to play Reign (via Twitter). In addition to that, the Worldkiller will play a major part in the series and could be a regular, at least just for the third season.