Krannus was a rare non-Force-sensitive male Pureblood Sith who served as a military commander of the Sith Empire during the Galactic War. Krannus was in danger of being left to die by his Sith parents, however, he was spared this fate by direct order of the Sith Emperor. Although Krannus was considered inferior to Force-wielding Sith, his heritage raised him above the ordinary Humans of the Imperial Military.
Krannus served as one of the Empire's highest ranks–Executor–and wielded his supreme authority as a fiercely-devoted servant of the Emperor who spared his life. On his dark master's orders, Krannus led a death-worshipping cult whose members believed the Emperor was a godlike being who will bestow immortality and unlimited power upon them–but only if they bring about the galaxy's destruction first.
To achieve this goal, Krannus went to Belsavis in order to destroy the whole planet to start the Emperor's ritual, but was stopped and killed by the Hero of Tython.