Asajj was a rare anomaly, a Night Sister who became a Jedi! But the death of her master made her fall and she becamw known during the Clone Wars as Supreme Commander and qusi-apprentice to Darth Tyranus (Count Dooku). Dooku used hee as general, assassin, inquistor, and enforcer, but then Palpatine called dor her death and he betrayed her.
Asajj fell in love with Quilan Vos, and returned to the Light Side, but as most love stories, hers ended in tragedy.