The battlecruiser was modified enough so that it was capable of fighting any EF76 Nebulon-B escort frigate to a standstill. Modifications included increases to the number of turbolasers, deck fighters, and armor thickness. The ship and its efficient crew made a strong argument to their future victims against resisting a Thalassian raid. The ship could also support at least two squadrons of Z-95 Headhunters.
In 11 ABY during an attempt by the Thalassians to raid the planet of Kerilt, the Harmzuay was accosted by the Imperial-class Star Destroyer Invidious. Its commander, the renegade Admiral Leonia Tavira, took great exception to the Slavers' attempt to encroach on what she saw as "rightfully hers" and used the vastly superior firepower of her ship to utterly obliterate the old Kaloth cruiser.