'Supergirl': SPOILER Returns in "Reign"

Reign may have made her debut tonight on Supergirl, but it was the appearance of another character, one that we haven't seen since Season Two's "The Martian Chronicles", that just as exciting for fans.

Spoilers for tonight's midseason finale of Supergirl's third season, "Reign", below.

Reign (Odette Annabel) arrived in National City tonight and began to make her presence known by quite literally marking her territory with her symbol. One of those markings was done crop circle-style, and the discovery of it required Kara (Melissa Benoist) to leave her own Christmas party to check it out. When Supergirl arrives at the site of the symbol things are already well in hand thanks to DEO Agent Vasquez (Briana Venskus.)

Agent Vasquez may be a minor character on The CW superhero drama, but she's been a fan favorite since she first appeared in the series' pilot episode. Vasquez has worked closely with Supergirl in the past, assisting the heroine as she battled Red Tornado as well as helped Kara eavesdrop on J'onn's (David Harewood) interrogation when it was discovered he was a Martian and not Hank Henshaw. The last time audiences saw Vasquez, she was proving that she wasn't a Martian during "The Martian Chronicles" last season.

And while fans are no doubt excited to see Vasquez back at the DEO, they aren't the only ones. Venskus took to Twitter ahead of tonight's episode to share a group selfie featuring herself with Leigh, Harewood, and Benoist, everyone looking exciting to be working together again as Venskus captioned the image "the Babes with the Power."

Hopefully, we'll get to see more of Agent Vasquez when Supergirl returns from its winter hiatus in January. From the way things left off tonight, it looks like Supergirl, the DEO, and National City in general will need all the help it can get when it comes to facing off with Reign. The episode ended with the Girl of Steel in pretty bad shape, leaving National City without a defense against the Worldkiller.

Supergirl airs Mondays at 8/7c on The CW. New episodes will return January 15th.