Presence

The Presence was a female Sith who once commanded the weapon on the Sith temple on the planet Malachor. In 3 BBY, her voice was heard by Ezra Bridger when he used a Sith holocron to inadvertently activate the superweapon. Bridger was led by the former Sith Lord once known as Darth Maul to believe that using the holocron would grant him the knowledge he needed to destroy the Sith. Once he activated the temple however, the Presence told him that the knowledge contained within the holocron was the power of the temple's battle station and that it had the power to destroy life.

Text and facts from the “Presence” article on Wookieepedia, licensed under CC BY-SA 3.0. Modified for this site.