Savage Opress was a male Dathomiri Zabrak who lived as a member of the Nightbrother clan on Dathomir. The brother of Feral, Opress was more commonly remembered as the brother of the Sith Lord Darth Maul. As a noble warrior, and one who cared for the well being of his kin, Opress was the leader of one of the Nightbrother tribes, who lived subservient to the Nightsister witches who lived on the other side of Dathomir. Following his transformation into a tool of the Dark side of the Force, Opress was a merciless brute who employed weapons such as the enchanted blade of the Nightsisters and a double-bladed lightsaber.
In 21 BBY, in the midst of the Clone Wars, Opress was handpicked by Asajj Ventress, a Nightsister warrior who served as a disciple to Darth Maul's Sith successor, Darth Tyranus, to be physically enhanced by the witchcraft of the Nightsisters after proving his worth in three trials to test his combat capabilities. Opress was then donated to Tyranus as a new apprentice, under the guise of being a complimentary gift from Mother Talzin, the leader of the Nightsisters.
In reality, Opress was implanted as a sleeper agent with the intention of killing Tyranus, a vehicle for Ventress' desire for vengeance. Mentally conditioned to obey Ventress, to the point of mindlessly killing his own brother Feral at her command, Opress nevertheless became an ally to Tyranus, single-handedly killing two Jedi and a squadron of clone troopers on Devaron. Following several sessions of brutal Sith training, Opress was deployed on a botched mission to abduct King Katuunko of Toydaria, which ended in his accidental murder. When the time came for Ventress to carry out her plot to kill Tyranus, Opress' hatred for both of his masters broke his brainwashing and allowed him to act independently.
A subsequent battle with Tyranus, Ventress and the Jedi Knights Anakin Skywalker and Obi-Wan Kenobi, the latter being the man who had killed Darth Maul on Naboo, left Opress wounded. Limping off to Dathomir, Opress turned to Mother Talzin for help. She claimed to Opress that he had a brother who was in exile in the Outer Rim. Talzin offered Opress a talisman that would lead him to his brother, and then Opress embarked on a personal journey to confirm that his brother was alive and to receive his help in destroying both Dooku and Ventress.