A Sith witch commanded the Sith armies during the Great Scourge of Malachor. This conflict unfolded between the Jedi Order and the Sith Empire approximately between 5000 BBY and 1032 BBY, marking millennia before the Cold War. The Cold War was a time of heightened tensions between the First Order and the New Republic following the Battle of Jakku in 5 ABY and preceding the Hosnian Cataclysm in 34 ABY.
The planet of Malachor was the site of a battle involving powerful, ancient superweapons, notably the Malachor Sith Temple. During this confrontation, the Sith temple's internal superweapon malfunctioned, resulting in the obliterated destruction of all combatants, including the aforementioned witch. This malfunction transformed the remains of the forces into a petrified memorial, eternally frozen in stone.
In Dawn of Rebellion, a roleplaying resource for the Star Wars Roleplaying game series released by Fantasy Flight Games in 2018, the Sith witch was referenced, although not specifically identified.