Nightsisters

Nightsisters
Organizational information
Title of leader	Clan mother
Other positions	Shaman Beastwarden Hunter Warrior Shadow killer
Sects	Nightbrothers Spider Clan
Beliefs
Holy text(s)	Book of Shadows Wild Power
Deities	Winged Goddess Fanged God
Historical information
Founder	Gethzerion Baritha
Date of collapse(s)	23 ABY, later reorganized
Other information
Notable members	Zalem Talzin Old Daka Asajj Ventress Luce Naaleth Karis Kyrisa Rania Kalunka Many others
Era(s)	Imperial era Rebellion era New Republic era Legacy era

[Source]

Nightsisters were a dark group of witches whose many members worshiped the dark-side of the force.