Hargrev was a male Human Sith Lord from the era of the Galactic War, serving the reconstituted Sith Empire. His gender was male.
Once an apprentice under Darth Silthar, Hargrev was viewed by certain high-ranking Lords as a near-madman, consumed by the pursuit of pain, fear, and ultimately, power. Consequently, he was not regarded with much respect and was not expected to ever achieve the title of Darth.
Regardless of these opinions, Darth Rictus of the Dark Council tasked Hargrev with leading an expedition to Oricon, a volcanic moon that served as the refuge of the dreaded Dread Masters following the demise of Dread Master Styrak on Darvannis. After the expedition went silent, Darth Marr sent the Empire's heroes, who had been involved in the Dread Masters' escape from their imprisonment on Belsavis, to re-establish contact.
Not long after his involvement on Oricon, Hargrev started to recognize the error of his ways. After witnessing the actions of the Dread Masters, he realized he wasn't as evil as he believed, and that the Masters had gone further than any being, even a Sith, should go. He realized that they had to be eliminated. Hargrev went through a transformation on the planet, becoming more concerned with the safety of those under his command and doing everything he could to prevent them from losing their sanity.
Following the Dread Masters' defeat, Hargrev gave the Empire's heroes the option to either salvage the Masters' technology or destroy it entirely.
Hargrev is a character featured in the 2011 video game Star Wars: The Old Republic. Imperial players encounter him during the Oricon storyline. When Imperial player(s) finish the Oricon missions and Operations, they are given a choice regarding the remaining Dread Masters' technology: they can choose to destroy it (resulting in light side points) or allow Imperial forces to occupy the Masters' fortress (resulting in dark side points).