Heirorius begun serving the Galactic Empire around 15 BBY, spending around twenty years working in the Empire's military. By 5 ABY, he served on the planet Dybbron III, which had split from the Empire's loyalists after the death of the Galactic Emperor in 4 ABY. That year, however, the 204th Imperial Fighter Wing, a unit serving under Colonel Soran Keize as part of the loyalist forces, sought to devastate the planet for going rogue. The fighter wing offered to accept willing recruits before the attack, and Heirorius willingly joined the unit to escape the destruction of civilization at Dybbron III.
Holding the rank of Lieutenant by that point, Heirorius was assigned to a comscan station at the bridge of the 204th's flagship, the bulk freighter Yadeez. The fighter wing soon traveled to the planet Fedovoi End, which had also split off from the Imperial loyalists under the rule of the breakaway faction Yomo Council. After the Yadeez and its escorts arrived before the world, Keize broadcast an announcement to Fedovoi End and Heirorius frequently looked over to Captain Oratio Nenvez.
When the colonel asked if there was any reply from the planet, the lieutenant reported no reply, but added that there were energy spikes, which he suspected were ion cannons being powered up. Keize subsequently had the bridge crew proceeded to relay orders for 204th assets to move in to begin the attack. The attack resulted in the 204th shattering Fedovoi End's ice caps, opening up gas pockets and poisoning the atmosphere and population.
Shortly after, the Yadeez and its escorts were pursued through a number of star systems by the New Republic refitted Star Destroyer Deliverance and its starfighter wing. The 204th vessels soon reached the ancient manmade ocean world Chadawa, another target of the unit which had split from the Imperial loyalists. When the 204th attacked the planet, it sheltered under Chadawa's cage of mechanical planetary rings, sabotaging satellites which channeled radiation while Deliverances wing attacked the unit.
During the fighting, Heirorius was at his station when Starfighter Commander Wyl Lark of the Deliverances wing contacted the 204th. The lieutenant waved to Keize and Second Lieutenant Commander Teso Broosh. Broosh asked Heirorius if it was Lark contacting, which the latter confirmed. The colonel and Lark then spoke, agreeing to have a one on one duel while their fighter wings held back. After Keize agreed on his end, he gestured Heirorius to close the comm channel.
Heirorius was appeared in the 2021 novel Victory's Price, the third and final volume of the Star Wars: Alphabet Squadron trilogy written by Alexander Freed.