Sid Uddra was a human female who worked as a loyalty officer within the Imperial Security Bureau, acting as a mentor to Sinjir Rath Velus. Hailing from Sixmoon in the Velusia system, Uddra chose Velus from an Imperial Academy to be trained as a loyalty officer because of his sharp mind and aggressive nature. Subsequently, Velus was moved to the ISB's training facility, known as the Viper's Nest, which was located on the ocean planet of Virkoi. Velus experienced a brutal training regimen under Uddra's guidance, which included regular physical fights and simulated torture. In one particular instance, Uddra even fractured Velus's toes to make him stronger.
Velus's initial mission as a loyalty officer involved interrogating Alster Grove, a Lieutenant in the Imperial Navy who was involved in a plot to remove Emperor Palpatine from power by assassinating his right-hand man, Darth Vader. Uddra tasked him with discovering the identities of the other members of the conspiracy. Velus, following Uddra's instructions, tortured Grove for a couple of nights until he revealed the names of his fellow plotters. Uddra herself killed Grove by casting him into Virkoi's oceans, while Lord Vader tracked down and decapitated Grove's fellow conspirators.