The Nightsisters of Dathomir are one of the most fascinating societies in the Star Wars galaxy. In Ahsoka, they finally got their chance to step into the limelight (or at least into the public eye) after appearing a few times in minor roles throughout the saga. They were seen working with the series' main antagonist, Grand Admiral Thrawn, as he determined how to return from his exile to a distant land. This is their first live-action appearance, and if the final scene of Ahsoka is to be believed, it's far from the last.
Source：https://www.cbr.com/ahsoka-nightsisters-start-legends/
