A male member of the Grysk species, a race known for its warlike nature, served as the commander aboard the Grysk StoneCrusher-class WarMaster named Armageddon. This warship belonged to the fleet commanded by the Grysk operative "Jixtus." Around 18 BBY, the Armageddon, accompanied by the other warships in Jixtus's fleet, arrived in the Sunrise system of the Unknown Regions, their movements precisely orchestrated by their Attendant navigators. Soon after their arrival, a battle erupted between the Grysk fleet and a fleet of Chiss starships. During this engagement, the Armageddon engaged the Chiss heavy cruiser Springhawk. After successfully intercepting all incoming breacher missile waves launched by the cruiser, Mid Captain Ufsa'mak'ro of the Springhawk remarked that the Armageddon's captain was exceptionally skilled.
The Springhawk attempted to retreat, with the StoneCrusher pursuing it relentlessly. However, before the Grysk ship could overtake the Chiss heavy cruiser, the Clarr light cruiser Orisson and the Chiss heavy cruiser Grayshrike deployed their breachers, which impacted the Armageddon with acid, causing significant damage. Shortly thereafter, the StoneCrusher was destroyed in the conflict.
The Grysk were first referenced in Thrawn Ascendancy: Lesser Evil, a 2021 novel written by Timothy Zahn as a part of his Ascendancy Trilogy.