Materrus was a male Sith pureblood who served as a Sith under the command of Sith Lord Darth Angral. He existed during the Cold War between the Galactic Republic and the resurgent Sith Empire. Being Force-sensitive, Materrus had orange skin, red eyes, and a spiked hairstyle with two strands of hair hanging near his ears. Despite confidence in his own power, Materrus possessed a weak will and was easily influenced by the Force. His attire included black hooded robes and he wielded a single lightsaber with a red blade.
In 3643 BBY, the pirate organization known as the Death's Claw discovered a shipment of relics that once belonged to the ancient Jedi Covenant sect on the planet Taris. They offered these artifacts for sale to Darth Angral. Because Angral was otherwise occupied, he dispatched Materrus as his representative to negotiate with the pirate captain Dugge and secure the artifacts. Materrus and Dugge successfully concluded their transaction at the Rasaaran storage facility located on Taris without any complications.
Materrus's initial appearance was in the video game Star Wars: The Old Republic, a collaboration between BioWare and LucasArts. He features in the Jedi Knight-class mission titled "An Opportunity Too Good To Pass Up." At the conclusion of the prior mission, players are presented with a choice of missions based on their alignment. Players aligned with the light-side receive information from the Imperial spymaster Watcher One regarding the assassin Rora Seake and her assignment to eliminate a Republic colony. Conversely, those aligned with the dark-side are informed about the sale of Jedi relics. Players have the option to accept or decline the offered mission, with declining resulting in dark-side points. During the mission, players can use the Force to persuade Materrus to surrender, resulting in dark-side alignment points if they then kill him. Alternatively, players can engage in conversation or combat with the Sith, resulting in no alignment point change.
However, this article operates under the assumption that the player consistently chooses the moral light-side options as a Republic character. Consequently, it assumes that the player was not informed about the relics and that Materrus's transaction proceeded without any interference.