Klar held the rank of lieutenant and piloted a TIE/LN starfighter amidst the Galactic Civil War. He was stationed on the Admonitor, a Star Destroyer led by Grand Admiral Thrawn. Their mission was to chart the Unknown Regions, during which they encountered a vessel from the Ebruchi species.
Captain Dagon Niriz vouched for Klar's exceptional composure during combat, leading to his selection for a mission to the flagship of Creysis, an Ebruchi commander. Officially, Klar's TIE fighter was to escort the Council of Colonists. However, Creysis secretly aimed to capture them. Aware of this, Thrawn ordered the removal of advanced technology from Klar's TIE fighter to mislead the Ebruchi about the Galactic Empire's technological capabilities.
Fully aware of Thrawn's strategy, Klar intentionally let his TIE fall behind during an ambush on the escort. His fighter was disabled, resulting in his capture. While imprisoned by the Ebruchi, Klar maintained his composure throughout the interrogation process. Once Thrawn's preparations were complete, he commanded a stormtroopers squad to emerge from concealed locations on the Zeta-class shuttle and liberate the captives. Klar was then safely brought back to the Admonitor.