Asajj Ventress
Asajj Ventress was a former member of the Nightsisters, a cult of witches from the planet Dathomir. She was sold into slavery as a child, but was eventually taken in as a Jedi Padawan by the Jedi Master who saved her. After her master's death in battle, Ventress fell to the dark side of the Force and became Count Dooku's informal Sith apprentice and personal assassin.
As a Sith assassin, she wielded two lightsabers with curved handles that could attach together and form a double bladed weapon with a curve in the middle. Originally a villain opposing the Jedi and the Galactic Republic, she was eventually betrayed by Dooku and, after a failed attempt to exact revenge on him, tried to distance herself from her old life by turning to bounty hunting. Despite her efforts, however, Ventress found herself drawn back into the Clone Wars when she helped her former Jedi enemies in various situations, slowly redeeming herself.