Hyllis was a Sergeant in the Galactic Empire's Stormtrooper Corps. During the Iron Blockade, in which Imperial Governor Adelhard blockaded the entire Anoat sector, Hyllis was stationed in a small garrison on the planet Mataou within the sector. The Sergeant was killed when a young smuggler attacked the garrison in order to create a distraction for the criminal Trade Spine League to sneak a ship through the blockade.