Merion, a male Human general, served the Sith Empire as a military leader during the era of the Galactic War. In the year 3640 BBY, he, alongside General Grann, found themselves stationed on Corellia. There, they spearheaded the Imperial military's efforts to seize control of Guardian Hold Four, aided by the Children of the Emperor. Nevertheless, their victory was short-lived as the Barsen'thor, in conjunction with the Rift Alliance, successfully retook the base, defeating both the Imperial Guard and Daresha, the Child of the Emperor stationed at the hold. Consequently, both generals were taken as prisoners, although Merion staunchly refused to assist his captors.
During the Battle of Corellia, both he, and his comrade General Grann assumed command of Guardian Hold Four. This was after Corporal Daresha, secretly a Child of the Emperor, had compromised the facility from within. However, their control was challenged by the Barsen'thor and his allied forces, launching an assault on the base not long after. Balmorran droids, under the Barsen'thor's direction, sabotaged the security systems of the Guardian Hold. Simultaneously, the Barsen'thor, along with a squad of Voss commandos, infiltrated the compound.
When the Barsen'thor made his entrance, Grann, Merion, and Daresha were all located in the Guardian Hold's conference room. Despite the valiant resistance of the Imperial garrison stationed at the location, the Barsen'thor successfully breached the conference room and defeated Daresha in a one-on-one fight. Shortly after, Republic forces apprehended Grann and Merion. Despite Merion's objections, Grann chose to cooperate with the Republic, revealing information that the First Son might be hiding in Guardian Hold One with the remaining members of the Corellian Council. The Barsen'thor then departed to pursue the First Son, while Grann and Merion were taken into custody.