The High Priestess was originally known as Fe Sun. She was a padawan of Shaak-Ti but was believed to have been killed by the criminal known as Lyshaa during the Clone Wars. Believing her master left her for dead, Fe Sun turned to the dark side of the Force and eventually revived the Bando Gora cult, intent on causing as much pain on the galaxy as she felt had been caused to her.
The High Priestess is the leader of the Bando Gora. Not much else is known about her at this time.