Supergirl continues to expand its mythos in season 2, and that means also expanding its cast of characters. However, it seems that plans for season 3 of the CW series are for Supergirl to have either a very powerful ally, or enemy - one that DC Comics fans will be excited about.
Word has come in that Supergirl's recurring character, Lena Luthor (Katie McGrath) is being bumped up to a series regular in season 3. Deadline broke news on the casting update - but it remains to be seen just how Lena Luthor will factor into the regular rotation of season 3.
The most obvious guess is that the season 2 storyline involving Lena's mother Lillian Luthor (Brenda Strong) and her organization, Project Cadmus, will climax with Lillian either being carted off to jail - or worse. Either way, it could be a development that put current friends Kara and Lena at serious odds, if Lena blames Supergirl for contributing to the ruin of her family.
Of course, an equally (if not more) intriguing turn would be having Lena ally with Supergirl and the D.E.O., and exploring a deeper friendship between the two - before the big turn toward the usual Kryptonian/Luthor rivalry we all know and love.
The Arrowverse shows have learned to set themselves at a nice forward pace, so we'd bet on the Kara/Lena rivalry being a big part of season 3's arc. It would be nice to see the classic comic book dynamic played out between the two characters, and Katie McGrath seems well suited to let the devil off the chain and be truly great Arrowverse villain. You can also catch her work on the big screen in the upcoming King Arthur: Legend of the Sword.