Aiolin Astarte was a female human engineered and trained by Doctor Cylo to replace the Sith Lord Darth Vader as Darth Sidious' Sith apprentice.
Aiolin and her twin brother Morit Astarte were born of the Astarte line of Celanon, who had joined the Separatist cause. The Astarte line funded much of Cylo's early work. Cylo thought of them as "generally smart" and "forward facing." Fearing retribution for their allegiance during the Clone Wars, the Astartes passed their children to Cylo for training and experimentation, in the hope of redeeming themselves. She also has a green lightsaber.