Astra

Astra was a recurring character and antagonist of the first season of Supergirl. Astra was a kryptonian woman, a former Fort Rozz Prisoner and The General. Astra was the twin sister of Alura Zor-El, the wife of Non, the unt of Kara Zor-El and sister-in-law of Zor-El. She is portrayed by the special guest starring cast member Laura Benanti.

Life on Krypton
Astra was born in Krypton with her twin sister Alura. Both loved each other and used to confuse their parents pretending to be the other.

Being Arrested
Astra commited some crimes to save her planet, so she was arrested and judged by her sister Alura that was heart broken for what Astra did.

Life on Earth
Astra arrived on Earth in the Fort Rozz and lived during 13 years planning to save the planet using criminal ways.

Season One
In Pilot, Astra was listening The Commander saying that Kara Zor-El defeated Vartox and she said that if they found her they should kill her.

Personality
Astra believed that she could save a planet but she used wrong ways such as killing. She was a strong and cold woman.