Jenar-Sei was a Voss male and held the rank of Commander, leading a team of Voss commandos. His unit conducted patrols in territories controlled by the Gormak during the era known as the Cold War.
Circa 3640 BBY, Jenar-Sei uncovered the Gormak's operation of extracting valuable Force crystals, which held immense significance for the Voss Mystics. These crystals were being utilized by the Gormak to tame wild creatures, turning them into weapons against the Voss people. At this critical juncture, while in the Halls of the Righteous, then under Gormak control, Jenar encountered the Barsen'thor and Gaden-Ko, from whom he requested assistance. Together with these newfound companions, Jenar successfully dismantled the Gormak's mining facilities and neutralized the local Gormak patrol units.
Having witnessed the capabilities of his allies, Jenar-Sei resolved to join the ranks of Gaden-Ko's followers, along with his squad. He then accompanied Gaden-Ko and the Barsen'thor in their ongoing conflict against the Sith Empire.