- Real name: Rachael Berkowitz
- Occupation: Rabble-Rouser and Super-Villainess
- Known Relatives: Chaim Berkowitz (father; deceased), Ida Berkowitz (mother)
- Group Affiliation: The Party for Social Reform
- Base of Operations: Chicago, Illinois
- Height: 5'8"
- Weight: 131 lbs.
- Eyes: Golden
- Hair: Red
Born in Warsaw, Poland in the mid 1930s to a simple Jewish tailor and his wife, Rachael Berkowitz saw her father gunned down by the Nazis, and then spent her adolescence in a German concentration camp. Over time, her mind grew more and more twisted, until she finally came to believe the Nazis' "Final Solution" had been correct.
Escaping to America at the war's end, the brilliant young woman received her first Ph.D at the age of 18. Years later, she unlocks the secrets of the Unified Field Theory, which thus enables her to tap into the primal forces of the universe, reshaping herself into the elemental being called Blackstarr.
Now possessing extraordinary powers, Blackstarr begins a political campaign of racist rhetoric that is designed to stir up anti-Semitic sentiment among the people. When Blackstarr's own people begin a riot during a public rally in Chicago's Grant Park, Supergirl arrives on the scene to quell the disturbance and restore order. Realizing that she faced the one person able to thwart her well-laid plans, Blackstarr attempts to destroy the Girl of Steel. During her encounters with Blackstarr, Supergirl in her guise of Linda Lee Danvers, learns that the villainess is in fact the daughter of her landlady, Ida Berkowitz. Their repeated clashes, however, lead only to Blackstarr's apparent destruction when she is seemingly torn apart by the conflicting gravitational fields of two miniature black holes. Without its leader, Blackstarr's Nazi-like Party for Social Reform soon after disbands, dying with their leader's monstrous dream. Supergirl makes one visit to Ida after the apparent death of Blackstarr to inform her of her daughter's passing. No words are spoken between the two, however, the looks exchanged between the two inform the aging woman of the tragedy and that she did not hold Supergirl responsible for her daughter's fate (SG2 No. 13, Nov 1983: "Echoes of Time Gone By!"; SG2 No. 14, Dec 1983: "Star Light, Star Bright...Blackstarr Rises Tonight!"; SG2 No. 15, Jan 1984: "Starrfall").
Powers and Abilities
By unlocking the secrets of the Unified Field Theory, a puzzle that even Albert Einstein was unable to solve, Blackstarr is able to tap into the very fabric of the cosmos, transforming herself into a being of almost infinite power. Among her abilities are the power to manipulate gravity, generate electromagnetic fields and fire concentrated barrages of photons, produce miniature black holes of awesome gravitational power, and teleport herself and anyone else she chooses over immeasurable distances. Possessed of these almost unimaginable powers, Blackstarr finds physical combat unnecessary and thus her skills in that department have never been measured.