Souske was a male Human who held the position of security chief aboard the Harrower-class dreadnought Oppressor, a warship belonging to the Sith Empire. This vessel served as the personal flagship of Darth Angral, a Sith Lord, during the Cold War with the Galactic Republic. Sporting fair skin, black eyes, and brown hair styled in a double stripe design, Souske's attire consisted of black Imperial soldier armor adorned with red markings, a common sight among members of the Imperial Military. He also wielded a vibrosword in combat. In 3643 BBY, Darth Angral launched an attack on Tython, a planet that served as the homeworld for the Jedi Order, intending to deploy the Desolator superweapon against it. However, a young Jedi Knight accompanied by the Padawan Kira Carsen managed to infiltrate the Oppressor while the Desolator was in the process of charging. Souske met his death while attempting to prevent the two Jedi from reaching the ship's bridge.
Souske's initial appearance was in the Jedi Knight storyline "Fate of the Jedi" within Star Wars: The Old Republic, a video game developed by BioWare and released in 2011. In this game, he is portrayed as an elite NPC stationed aboard the Oppressor, whom the player must defeat to progress towards Darth Angral.