The Destroyer contained a meditation sphere from which Kaan could direct fleet operations with battle meditation. Its bridge crew had all been hand-selected by Kaan and were absolutely loyal to him. Admiral Adrianna Nyras was its military commander.
Nightfall led the Sith fleet, striking from Kashyyyk, which captured Ruusan from the Galactic Republic in the First Battle of Ruusan in 1002 BBY.
At some point, it departed that world to lead the Coreward advance of the Sith fleet in a campaign which saw the conquest of the Bormea sector, including Chandrila, Corulag, and Brentaal IV, as well as the key intersection of the Hydian Way and the Perlemian Trade Route.
Nightfall, with Kaan, was thus absent when the Jedi Army of Light led by Lord Hoth retook Ruusan in the Third Battle of Ruusan. Alerted at Brentaal by Lord Kopecz, Kaan abandoned his plans for a push towards Coruscant itself and returned to Ruusan.