Drawing strength from their connection to the planet-or more accurately, the altar they had built in one of its caves-the Nightsisters ruled over Dathomir and over a clan of Zabrak males known as the Nightbrothers. The Nightsisters enjoyed an uneasy alliance with the Sith, with Darth Sidious having bargained with them for some of their lore while also taking Maul from among the Nightbrothers to serve as his apprentice. A young Nightsister named Asajj Ventress was also taken from the clan at a young age, and eventually found her way into the service of Sidious and his apprentice, Count Dooku, until Sidious came to regard her as a potential threat and ordered her elimination. Asajj soon made her way back to the Nightsisters, and they orchestrated a scheme to take revenge; after a failed assassination attempt, they selected Maul's brother Savage Opress to be offered to Dooku as a new assassin.
In reality Savage's purpose was to help Asajj destroy Dooku, but when the moment came Savage was turned against both his would-be masters; he then returned to Dathomir and was informed of his brother's continued existence, and thus set out to find him. Meanwhile, the treachery of the Nightsisters was answered with an attack by the Separatist Droid Army under General Grievous, who succeeded in eliminating all of the Nightsisters but their leader Talzin, who was Maul's mother, and Asajj, who briefly took up bounty hunting before perishing in another failed attempt to kill Dooku. Talzin later aided Maul and Savage in their efforts to build an empire to rival the Sith, but she and Savage eventually perished at the hands of Sidious. Maul was thus left the only surviving member of the clan, though the spirits of the fallen Nightsisters continued to reside in their altar.
Eventually, Maul's efforts to see the complete vision shown him by a merging of Sith and Jedi Holocrons resulted in him making a bargain with these spirits, whom he promised flesh and blood with which they could rebuild their order. In truth, Maul had no intention of fulfilling this promise, but was content to leave Kanan Jarrus and Sabine Wren to pay his debt when they came to Dathomir in search of him and Ezra Bridger, whom he had blackmailed into helping him. Ezra was able to force the Nightsisters to leave his friends, and then destroyed the altar using his own Lightsaber and Maul's Darksaber, seemingly ending the threat of the Nightsisters for good.
- "Visions and Voices" (First appearance) (Appears as a spirit)