Darth Vilus, a Sith Lord of either Human or Sith pureblood heritage from the re-emerging Sith Empire, met his end prior to the Cold War, but not before authoring more than three thousand tomes during his existence. He had multiple apprentices, one of whom, his fourth, met his demise at Vilus's hand after being discovered engaging in espionage. Following his utilization of the Force walk ritual, he was plagued by the voices of trapped Force ghosts, prompting a quest for a remedy. He unearthed a forbidden ritual on the planet Voss capable of mending shattered minds, documenting this technique in his writings. Regrettably, before Vilus could validate his discovery, he succumbed to madness.
Years afterward, Kallig, a Sith Lord grappling with a comparable affliction, stumbled upon Darth Vilus's texts within Darth Thanaton's private library and journeyed to Voss, where they effectively executed the ritual, thereby gaining dominance over the spectral entities within their psyche.