The Hank Henshaw version of the character is better known to comic book fans as Cyborg Superman, a one-time CIA agent who now runs the Department of Extra-Normal Operations (DEO,) which tracks down extraterrestrial threats on Earth.
Alexandra Danvers is the confident foster sister of Kara. Fascinated by Kara’s powers from a young age, Alex developed a lifelong obsession with science that inspired her to become a doctor.
In addition to the casting news it appears that Arrow and The Flash’s Andrew Kreisberg has joined Greg Berlanti and Ali Adler as a writer and executive producer on the show.
Here’s the official synopsis for the show:
Supergirl focuses on Kara Zor-El, Superman’s cousin, who was born on the planet Krypton and escaped amid its destruction years ago. Melissa Benoist will play Kara, who after arriving on Earth was taken in by a foster family, the Danvers, who taught her to be careful with her extraordinary powers.