When Asajj Ventress was betrayed and left for dead by her old master, she returned to Dathomir, wanting revenge. Mother Talzin selected Naa'leth and Karis to accompany Ventress to assassinate Dooku, which failed.
Later in the war, after Ventress once again returned after being forsaken by Dooku, and her tool in her plot for revenge, Savage Opress, she returned to Dathomir where she was welcomed by the Nightsisters. Wanting revenge against the Nighsisters, Dooku sent General Grievous to kill Ventress and the other Nightsisters. The Nightsister at first were loosing the battle until Old Daka called upon the undead to assist them. The Nightsisters gained the upperhand again but when Dooku ordered Grievous to kill Mother Talzin, he killed Old Daka in the process, which stopped the spell and caused the dead Nightsisters to fall. While Talzin and Ventress escaped, Naa'leth and the rest of the clan were massacred.