Darth Nihilus is one of the two secondary antagonists (alongside Darth Sion) of the 2004 video game Star Wars Knights of the Old Republic II: The Sith Lords.
He was a powerful and enigmatic Sith Lord who became a living wound in the Living Force following the destruction of his homeworld of Malachor V at the end of the Mandalorian Wars. He would gain enormous power, but also developed an endless hunger that would lead him to consume entire worlds just to survive.
Found by Darth Traya, she trained Nihilus to control his newfound powers, alongside her other apprentice Darth Sion. Eventually, the two apprentices conspired against their master and banished her from the Sith Triumvirate, with Nihilus becoming its leader in turn. True to his name, Nihilus was a nihilist supreme, seeing all life as beneath him and all but a feast to devour to satiate his endless hunger.