After learning of a recently captured prisoner, Yularen accompanied Thrawn and Governor Arihnda Pryce to interrogate him, only to find his cell empty. Yularen was later summoned by then Grand Admiral Thrawn to help ferret out the Rebellion mole known as Fulcrum, during which he was reunited with Kallus. Thrawn also proved invaluable in joint operations with the ISB, to the point that Yularen offered the Chiss a position with the organization in the event he was expelled from the navy, commenting that Thrawn 'would look good in white.' Yularen would also work with the Chiss officer Thrawn, putting ISB resources to work to keep him from being drummed out of the Imperial Navy for his radical tactics. Yularen eventually became a Colonel in the Imperial Security Bureau following the reformation of the Galactic Republic into the Galactic Empire, and became rather well known, with Yogar Lyste commenting that 'no traitor escapes the keen eye of Yularen.' Among his students would be future Agent Kallus, whom he regarded as a star pupil and whose career he kept track of afterwards.
Yularen, a by-the-book operator, was often frustrated with Skywalker's recklessness.
Wullf Yularen served as an Admiral during the Clone Wars for the Republic, operating under Jedi General Anakin Skywalker frequently.
