Unidentified Sith witch

Millennia before the Galactic Civil War, a Sith witch led Sith forces during the Great Scourge of Malachor, a battle between the Jedi Order and the Sith Empire. The battle involved ancient superweapons, including the Malachor Sith temple. The battle ultimately resulted in the Malachor Sith temple being activated and fired, petrifying and killing the combatants&mdash;both Jedi and Sith.

Behind the scenes
The unidentified Sith witch was first mentioned in Dawn of Rebellion, a canon roleplaying sourcebook that supplements Star Wars Rebels and Rogue One: A Star Wars Story by Fantasy Flight Games.