Major Lio Partagaz oversaw Imperial Security Bureau meetings in the Central Office on Coruscant at the height of the Empire’s reign. Partagaz had little patience for long-winded arguments or overly emotional reactions from his reports, instead demanding proof and clear plans of action in their fight to stamp out rebel activity.

Seeing anti-Imperial actions as a disease that could easily spread unchecked, Partagaz pushed ISB supervisors to remain vigilant in their work and encouraged ISB Supervisor Dedra Meero in her efforts to prove a pattern in rebel activity throughout several sectors of the galaxy. He called for an emergency meeting and retaliatory plans after a rebel cell’s successful heist of the Imperial payroll from an Aldhani base, and reassigned the Ferrix system to Meero when she reported her findings there. After overseeing an operation that took down a rebel group led by Anto Kreegyr, he encouraged Meero to find Axis on Ferrix – a mission that went down in flames after a revolt against the Empire by the local population.

Partagaz was an attendee of Orson Krennic’s secret meeting in the Maltheen Divide that focused on Ghorman and the Empire’s need for the mineral kalkite found in the planet’s crust. After Krennic appointed Dedra Meero to run a secret project to manipulate the Ghor, Partagaz assured her the role was one she couldn’t turn down and was a gift she should embrace. While supervising Meero, Partagaz used his superlative managerial skills to tamper Meero’s volatile emotions as the Ghorman mission progressed, and reminded her to keep the mission’s true objective hidden from Syril Karn, who had been stationed on Ghorman to assist her.

While monitoring the Ghorman project, Partagaz continued to push his reports to track down the Axis rebel network and other anti-Imperial activity. He later broke the news to Meero that after finding no substitute for Ghorman kalkite, the mining of the planet would soon begin. He assured Meero that a successful end to this initiative would solidify both her standing with the ISB and the ISB’s importance to the Emperor.

Later, Partagaz learned of Lonni Jung’s murder and Dedra Meero’s botched attempt to arrest Luthen Rael. After the failed ISB attempt to capture Kleya Marki and the suspicion that his department was harboring a secret rebel spy, even Krennic was unable to save Partagaz from the consequences of his office’s downward spiral.