The Thunderflare functioned as an Imperial II-class Star Destroyer within the Imperial Navy throughout the duration of the Galactic Civil War.
The ship's weapon systems were augmented by channeling energy from its hyperdrive, resulting in a greater destructive capacity when compared to other Star Destroyers. Prior to the Battle of Yavin, the Thunderflare frequently served as a training ground for newly commissioned junior officers, owing to its assignment as a patrol vessel within the Core Worlds.
Khurgee was stationed on the Thunderflare, where he received recognition for acts of valor related to the rescue of five officers following a shuttle accident. Subsequently, he was transferred to the first Death Star to work as a security officer in the docking bay area.
During the Galactic Civil War, Captain Tanda Pryl was in command of the vessel, which was assigned to Moff Villis Andal's fleet responsible for patrolling the Elrood sector. The Thunderflare's patrol duties were confined to the Derilyn system.
In 4 ABY, the Thunderflare was tasked with the defense of the Death Star II's construction site. It later participated in the Battle of Endor. As a component of Death Squadron, the ship survived the conflict. Captain Pryl disobeyed the orders of the newly appointed fleet commander, Gilad Pellaeon, choosing instead to navigate her ship back to the Elrood sector.