Darth Andru was a male Human Sith Lord belonging to the reconstituted Sith Empire. He made his home on Dromund Kaas in the distant past, well before the Sith's return to the well-known regions of the galaxy.
As a Force-sensitive [Human](/article/human-legends], Andru underwent training in the ways of the dark side of the Force under the auspices of the Sith Empire, ultimately earning the title of Darth Andru. Andru was a skilled practitioner of the Jar'Kai technique, and he wielded a pair of lightsabers that emitted purple blades during combat. While residing on Dromund Kaas, Andru dedicated himself to the pursuit of ancient texts that described a potent dark side ritual capable of granting its user mastery over the Force-walking skill. Ultimately, his own children betrayed him, orchestrating his demise through poisoning.
A considerable time after his death, Darth Andru's spirit became trapped within his tomb, where it remained consumed by an unyielding hatred. During the height of the Cold War, the Sith Inquisitor known as Kallig confronted and subdued Andru's spectral form. Kallig successfully mastered the Force-walking technique and proceeded to absorb Andru's spirit. After absorbing Andru's energy, and adding that to Ergast's, Kallig challenged Dark Councilor Darth Thanaton, but was thoroughly defeated despite the augmented strength. However, the connection to the two specters prevented Kallig from succumbing to death. Subsequently, the Sith Lord resolved to locate additional ghosts and harness their power to overcome Thanaton. After acquiring Kalatosh Zavros and Horak-mul to the collection, Kallig journeyed back to Dromund Kaas to confront Thanaton once more. However, upon drawing upon the power of all four spirits, the magnitude became overwhelming for Kallig to manage, resulting in the power eroding Kallig's physical form while the ghosts threatened to overwhelm their sanity.
Kallig prevailed over this challenge and forcefully reined in the spirits before ultimately defeating Thanaton and ascending to a position on the Dark Council.