Darth Nihilus was a Dark Lord of the Sith who lived during the Old Republic Era. He was trained by his master Darth Traya, through which he became a member of the Sith Triumvirate known as the Lord of Hunger. Unlike most Sith he didn't care for the organization, instead craving greater power and the death of the Jedi. Nihilus had one apprentice during his lifetime, Visas Marr, who betrayed him preceding his death in 3,951 BBY over Telos IV.
According to historical events told in The Sith Lords, Nihilus was extremely powerful in the Force. He wiped out the entire planet of Katarr solely through the Force, by sucking the Force out of every living thing on the planet. The whole planet became an empty shell, where no life could flourish - except for one sole surviving Miraluka, Visas Marr. The miracle of her survival intrigued Nihilus as he later made her his apprentice, and a strong bond would form between the two.