Sade is a teleporting assassin with lightning fast reflexes. She is a an arms expert and considered to be very dangerous.
After carrying out many successful assassinations on Earth, Sade was eventually apprehended while trying to kill the Dominator ambassador to Earthgov.
Sade was eventually freed by the S.U.B.S. and became an ally to them and the Legion of Super-Heroes.
Sade eventually had an extremely violent altercation with Bounty when Bounty tried to claim the bounty on Sade. This ended when Sade shot Bounty multiple times, forcing the Bounty entity out of Dawnstar's body, which it had been possessing.
Sade's first name may be "Monica" or that may just be one of many aliases.