Ku Vrat was a Blood Carver killer, previously associated with the Bounty Hunters' Guild. During the time of the Second Imperial Civil War, he later found employment under Black Sun Vigo Lun Rask.
Living more than a century after the Battle of Yavin was Ku Vrat, a Blood Carver. The Blood Carvers were a species of warriors known for their bloodlust and reputation as assassins and bounty hunters; Vrat followed this path, becoming a member of the Bounty Hunters' Guild.
Vrat was dedicated to the hunt, but preferred to operate independently. This proved detrimental when he killed his brother during a hunt; it was believed his brother was an obstacle to Vrat's target. As punishment for this act, Ku Vrat was exiled by his people. The Bounty Hunters' Guild followed suit, expelling him for interfering with other hunters' bounties, violating the Bounty Hunters' Creed.
By 137 ABY, Vrat had secured employment with Black Sun. He served as an assassin for Black Sun Vigo Lun Rask, operating from Rask's fortress on Kaer. He became one of Rask's most trusted and skilled killers, alongside Anzati spouses Sint and Nakia Yoru.
In 137 ABY, Lun Rask assigned Vrat, along with the married Anzati couple Sint and Nakia Yoru, to assassinate both former Jedi Padawan Cade Skywalker and Imperial agent Gunn Yage. Nieve Gromia, the Imperial Moff of the Arkanis sector, had provided information revealing that Black Sun pirates had been stealing Imperial shipments for months. However, Skywalker and his crew began to interfere and seize the cargo, disrupting the arrangement between Rask and Gromia. Agent Yage was dispatched by Moff Nyna Calixte to assist Gromia in stopping the pirates.
Vrat located the targets at Gusha's Luck, a cantina in Mos Eisley, and intended to eliminate them. However, the Yorus intervened, reminding him of their orders for discretion and suggesting a collaboration. Despite his distrust of the Anzati couple, Vrat agreed. The three assassins trailed Skywalker and Yage to the Jundland Wastes and attacked them after Skywalker used the Force to choke Yage, causing her X-34 landspeeder to crash. Nevertheless, the pair escaped during a sandstorm. Vrat blamed the Yorus for the targets' escape, as they had fired at them without intending to kill. Vrat and Sint engaged in a brief skirmish, which Nakia halted. She explained to the Blood Carver that once she and her husband caught the scent of their prey's luck, they could track them. She also offered Vrat the credit for the assassinations, as she only desired to feed on Skywalker's soup.
The trio tracked their targets to the abandoned Lars homestead, where a battle ensued. Ku Vrat engaged Morrigan Corde and Jariah Syn, who had arrived at the scene. Corde shot Vrat with a poison dart, and Syn delivered the final blow with two thud bugs.