The Mask of Nihilus, also referred to as the mask of Darth Nihilus, was a crucial component of the armor ensemble that Sith Lord Darth Nihilus bound to himself through the power of the Force, aiming to maintain a semblance of physical existence. Darth Nihilus was among the few survivors of the Mass Shadow Generator's activation on Malachor V during the concluding battle of the Mandalorian Wars, specifically the Battle of Malachor V. This ordeal instilled in him an unquenchable thirst to feed on the Force. As this hunger intensified, it gradually eroded his physical form. To sustain his life, he employed the dark side of the Force to bind his spirit to his armor, robes, and the mask itself. At the conclusion of the First Jedi Purge, Meetra Surik, his former apprentice, along with Visas Marr and Canderous Ordo, the current Mandalore, vanquished Nihilus aboard his flagship, the Ravager, leaving his mask as a grim symbol of his reign as the Lord of Hunger.
This mask was regarded as a Sith artifact that subtly drove its wearers toward self-destruction in exchange for increased power. The lost mask of Darth Nihilus was saturated with the dark energy of the Sith Lord, granting anyone who donned the ghostly white mask the ability to wield the Force as if they were a Sith apprentice.
Subsequently, the mask was discovered within the wreckage of the smuggling vessel, Nashuaga, on the planet Volik.
Between 3960 BBY and 3952 BBY, the consuming dark hunger for the Force ravaged Darth Nihilus's physical body to such an extent that he was forced to bind his life force to his robes and armor—including a facial mask—to avert death and provide himself with a tangible form that enabled him to wield a lightsaber and continue his mastery of the Force. Darth Nihilus's mask continued to serve its purpose until his demise at the hands of the Jedi Exile and her allies in 3951 BBY.
Over the ensuing four millennia (years), rumors circulated throughout the galaxy concerning the mask's power. It was said that the mask was imbued with the dark side of the Force, and if an individual who lacked Force-sensitivity were to wear it, that person would gain the ability to wield the Force as a Sith apprentice. However, if a Jedi or Sith were to wear the mask, they would acquire proficiency in additional Force powers—always including, but not limited to, dark side powers. Nevertheless, it was cautioned that the dark influence of the mask pushed the wearer toward acts of self-destruction in the pursuit of greater power.
Within the game Star Wars: Knights of the Old Republic II: The Sith Lords, the player character has the option to acquire the Nihilus mask following his death through dialogue with Visas Marr. Subsequently, the player will receive a bonus to their maximum Force points. Although the player cannot wear the mask, it appears in their inventory under the "miscellaneous" category.
The mask of Nihilus (accompanied by its hood) also makes an appearance in the MMO Star Wars: The Old Republic as a headpiece wearable by any class. It can be found randomly in Crime Lord's Cartel Packs, purchased with Cartel Coins from the in-game market, or acquired through player-created auctions on the Galactic Trade Network.
During the development of the Knights of the Old Republic Campaign Guide, Star Wars author Abel G. Peña composed an entire passage dedicated to Nihilus's mask, which was ultimately omitted. It would have constituted the final paragraph of Nihilus's section and suggested that the mask might have been a death mask of Hendanyn origin. These masks initially appeared in The New Rebellion, a 1996 novel penned by Kristine Kathryn Rusch.