Darth Nihilus is the infamous Sith Lord from the video game Star Wars Knights of the Old Republic II: The Sith Lords. He is the shadowy figure that wears a red and white ghost mask and is dressed in a black cloak.

It has been revealed that Darth Nihilus consumes the Force from Force-sensitives in order to stay alive. He can even consume entire Force-sensitive planets.

Little is known of Nihilus's true beginnings, other than the fact that he was a survivor of the Mandalorian Wars, and may or may not have at one point been a prisoner of the Mandalorians. After the war he was found by Darth Traya to be Force-sensitive, and she began training him in the ways of the Sith at the Trayus Academy on Malachor V. After his true powers and potential were realized, Nihilus, along with fellow Sith student Darth Sion, plotted and turned against their dark mistress Traya. They cast Traya down, stripped her of her power, and expelled her from the Sith Order. Nihilus and Sion had now begun their shadow war against the remnants of the Jedi Order. They hunted Jedi to the brink of extinction.

Darth Nihilus ravaged and consumed whole worlds, to feed his insatiable appetite for power, from the bridge of his flagship, the Ravager. Nihilus's powers were so all-consuming that all those who came into contact with the Sith Lord became slaves, mindless servants to his will.

One such servant of Nihilus was Visas Marr, a Miraluka female from Katarr, a planet consumed and destroyed by Nihilus. The Sith Lord sent Visas on a mission to find and bring the last of the Jedi before him, so that he could consume his power and essence. However, this would be the mighty Sith Lord's undoing, for the Jedi exile broke her from Nihilus's bonds, and she turned against her former master. Along with the exile and Mandalore, she defeated him on board the bridge of the Ravager. After his death, his body dissolved in an aura of dark side energies.

What happened to Nihilus after his body dissolved is unknown. Whether he is truly gone, or should return again to challenge the Jedi and the Republic, shall remain a mystery. Interestingly, his true identity is not revealed even when Visas looks at his face after his defeat, leaving questions about whether his previous personality may have been anyone of consequence.

Like most of the Sith Lords, Darth Nihilus's name has some meaning (nihil is Latin for nothing). He has no loyalties to anyone but himself, and will consume both Sith and Jedi with his hunger, which notes that his name fits his current personality quite well.