|Season 3, Episode 4|
Power Girl is the fourth episode of Supergirl Season 3 and the 46th episode overall. It is the fourth part of the 4-part Kandor storyline that opens the season.
KAREN COMES TO NATIONAL CITY- When Karen arrives in National City, Kara attempts to get the disoriented and violent Kryptonian under control. Meanwhile, Alura speaks with Lena, Astra helps Alex and J'onn fend off an attack by Cyborg Superman, and Maggie meets up with Lucy and Lesla.
- Melissa Benoist as Kara Danvers/Supergirl
- Chyler Leigh as Alex Danvers
- Jeremy Jordan as Winn Schott
- Katie McGrath as Lena Luthor
- Laura Benanti as Alura Zor-El/Astra In-Ze
- Tyler Hoechlin as Cyborg Superman
- Floriana Lima as Maggie Danvers
- Zachary Quinto as General Dru-Zod
- Odette Annable as Samantha Arias/Reign
- Amy Acker as Brainiac (voice)
- Harry Lennix as Commander Gor
- Chris Vance as Non
- Tracy Spiridakos as Lesla-Lar
- Michael Rosenbaum as Lex Luthor (dream)
- Chad Lowe as Thomas Coville
- Paige Turco as Lara Lor-Van
- Casper Crump as Vandal Savage
- Jenna Dewan as Lucy Lane
- Lauren German as President Veronica Banks
- Emma Tremblay as Ruby Arias
- Robert Gant as Zor-El
- Wallis Day as Nyssa-Vex (credit only)
- with Claire Holt as Karen Starr
- and David Harewood as J'onn J'onzz
Special Guest StarsEdit
- Briana Venskus as Agent Susan Vasquez
- Antagonists: Cyborg Superman, Thomas Coville
- Clark and Nyssa do not appear in this episode.
- Cat was last seen in Lines.