Sanitarium The Sanitarium was the only structure remaining on the surface of Nathema in the centuries after the Ritual of Nathema destroyed all life on the planet . The Sith Emperor Vitiate continued to the use the Sanitarium for his own purposes during the following centuries , building a secure vault that kept some of his most - guarded secrets . He experimented with training Force - users to survive the void in the Force , resulting in Nathema Zealot s , who became guards of the Sanitarium , while day - to - day affairs were being taken care of by specially trained Abyssin Keepers . The powerful Force - users who opposed Vitiate were send to Sanitarium to be experimented upon , unable to access the Force to resist or escape . Eventually , Vitiate send his daughter Vaylin to the Sanitarium to subject her to mental conditioning , she became the only inmate to ever leave the Sanitarium alive . Years later Vaylin assumed her father ' s Eternal Throne and became aware of her mental conditioning , ordering Jarak , the scientist responsible for it , to find a way to undo it . After Jarak had a breakthrough , he invited Vaylin to return to Nathema and subjected her to a ritual of his design . However , it did not go as intended and Vaylin ' s power raced out of control , killing everyone in its path . She eventually found the will to break her bonds and left the surface of Nathema , after which she used the Force to remotely trigger the destruction of the Sanitarium . History . After the Ritual of Nathema wiped out all life on the planet and left a void in the Force on Nathema , Vitiate located one of his secret vaults there , storing artifacts even he deemed too dangerous to use . This included a holocron that contained the essence of his father Dramath , whom Vitiate continued to torment over the following centuries . He also brought groups of Force - sensitives to the planet , forcing them to brave the Force void in an effort to create an army of incredibly powerful but utterly subservient Force users . However , his efforts were only partially successful ; the final result was the Nathema Zealot s , a group of Force users who survived contact with the void through a daily regime of rituals and meditation that focused their power , while also diminishing their free will . The disadvantage of such a process was that the Zealots became actually dependent on the void for their survival , becoming catatonic if they left the planet ' s surface . Nonetheless , Vitiate repurposed the Zealots as guards for the Sanitarium , build above the vault . Vitiate used the void left in the Force on Nathema to keep powerful Force - users who opposed him in the Sanitarium , where they could be experimented upon , unable to use the Force to escape or resist . Apart from Nathema Zealots , the Sanitarium was home to specially trained Abyssin Keepers , who kept watch over the facility ' s day - to - day order . The vault was guarded by native Voreclaw s , while the halls were patrolled by mutated creatures from other worlds , who were genetically engineered to instill fear , terror , and obedience . Around the time of the Treaty of Coruscant Vaylin , the daughter of Vitiate ' s alter - ego Valkorion , had shown both immense strength in the Force and an inability to control it . Seeing her as danger to others and a threat to his plans , Valkorion send Vaylin to the Sanitarium on Nathema to teach her obedience . Anomid scientist Jarak was given a laboratory in the Sanitarium and a free reign over Vaylin . Jarak subjected Vaylin to many horrors during her stay in the Sanitarium , as she was tested both physically and mentally in constant fear , pain and isolation . Eventually Jarak exhausted conventional methods and subjected Vaylin to torture by machines of his own design . In the end , Vaylin ' s mind was broken and while she herself became a cruel , vindictive person prone to temper tantrums , she remained unaware of the true purpose of her stay in the Sanitarium - being conditioned to become powerless against whoever spoke the phrase " Kneel before the Dragon of Zakuul " in her presence . Vaylin ' s mother Senya Tirall at one point attempted to rescue her daughter from the Sanitarium , but was stopped by Valkorion before she could take her daughter offworld . Vaylin spend years in the Sanitarium , during which her brother Thexan was the only one to visit her and bring her gifts . Eventually , her other brother Arcann brought her back home to Zakuul , which remained his only visit to Nathema . Years came by and Valkorion was eventually killed , his Eternal Throne assumed first by Arcann , and then by Vaylin . After a confrontation aboard the " Gravestone " made Vaylin aware of her conditioning , she contacted Jarak again and used her new authority as the Eternal Empress to order him to find a way to break her conditioning . Jarak returned to Sanitarium , where Vaylin provided him ample test subjects . Eventually Jarak informed Vaylin that he had made a breakthrough and Vaylin soon came to Nathema , where Jarak explained that the process to break her conditioning would be even more extreme , with nobody else surviving it so far . Unaware that the Alliance Commander had followed her to Nathema attempting to stop her , Vaylin agreed to the process . However soon after it started , it proved to be highly unstable , resulting in her power erupting through the Sanitarium . The Void corruption was impossible to contain , and spread like wildfire , draining and killing anyone it came into contact with . Even Valkorion , an incorporeal Force entity , was not immune to its effects . Jarak himself escaped , but was confronted by Lana Beniko and the Alliance Commander . Jarak brought the two to the Emperor ' s Vault , where before he was killed by a vault guardian , he gave them a helpful suggestion on how to restore the Vault ' s power , allowing them to eventually get out . While Beniko and Alliance Commander were restoring the power and investigating Dramath ' s holocron , Vaylin successfully broke her bonds and left the Sanitarium , unaware of their presence . Once in orbit , she used her newfound power to trigger to destruction of Sanitarium through the Force . Beniko and Commander barely managed to escape the Sanitarium right before the last structure on Nathema was destroyed . Behind the scenes . Sanitarium first appeared in " Betrayed " cinematic trailer . It was visited again in " " Chapter VII : Into the Void , which elaborated on its backstory .