Deag Nilox is a character in Doom Eternal and one of three Hell Priests.
He once served as a holy Sentinel Priest in Argent D'Nur and had been the first to discover and manipulate the gateways to Hell. However, he became corrupted by Hell's influence and the taste of Argent Energy and now follows the orders of the Khan Maykr.
In his quest for vengeance agaisnt Hell and its denizens, Doom Slayer tracked Deag Nilox's fortress on Earth. Storming it before me had made his way to his inner sanctum and slew him with the help a holy medallion. Nilox's severed head is later procured as a trophy and placed in the Fortress of Doom; home to the hellwalker.