Born Shira Brie, Lumiya took the role of Dark Lady of the Sith after the apparent demise of Darth Sidious at the end of Return of the Jedi and her story is truly one of the best the now non-canon Legends has to offer.
Formerly an Imperial double agent, Lumiya infiltrated the Rebel Alliance only to suffer grievous injuries during a dogfight. As is the norm for the Star Wars franchise, she was rescued from her destroyed TIE Fighter and fitted with numerous mechanical prosthetic parts to keep her alive - Palpatine loves an android!
Having outlived both Sidious and Vader, Lumiya's role as Dark Lady of the Sith led her to seek out and destroy Luke Skywalker. Hellbent on revenge, Lumiya even corrupted Skywalker's nephew: Jacen Solo into joining the Sith before meeting her demise at Luke's hand