He holds the position of Liege Centuro within the Empire and is the commander of the battalions working on cyberforming the K-Tor Galaxy. His goal is to cyberform every planet in the universe, leaving Transformers as the only remaining lifeforms.
Jhiaxus was one of the many Transformers born through the process of budding after Optimus, Megatron and their respective crews left Cybertron. Jhiaxus left Cybertron alongside his comrades to form a new empire. At some point he and the rest of the budded Cybertronians encountered the Liege Maximo, who bestoyed upon Jhiaxus the rank of "Liege Centuro".
Jhiaxus's crew later abducted a team of Autobots led by Optimus Prime and brought them aboard his flagship, Twilight. Jhiaxus explained to Optimus the history of the Cybertronian Empire and their goals, hoping to persuade Optimus into joining his side. Optimus rejected Jhiaxus's ideals, however, and escaped along with his Autobots aboard a stolen ship. Jhiaxus took several members of his crew aboard a ship to follow them.
Jhiaxus followed the Autobots to the K'tord Nebula, where both crews were infected by Shadow parasites. Jhiaxus formed a truce with Optimus to get rid of the parasites and let his crew go unfollowed after they had succeeded in purging the shadow parasites. Jhiaxus later bombed the parasites and returned to the Twilight.
Jhiaxus later captured Grimlock and his small team of Autobots after they attempted to plant a Chaosmaster Bomb aboard the flagship, and shipped the captured Transformers to Liege Maximo so he could examine them.
Jhiaxus later led an attack on the Decepticons stationed aboard Warworld, with Jhiaxus engaging Megatron in a dogfight in orbit of the planet Tykos. Jhiaxus nearly killed Megatron, and his troops succeeded in defeating the Decepticons.
Jhiaxus later tried to draw out the Autobots by cyberforming more planets. While the attempt succeeded, and the Autobots were intially overwhelmed, the Cybertronians were pushed back by the Decepticons, who had formed a truce with the Autobots to fight the Cybertronian Empire.
Jhiaxus later made a deal with Starscream, promising him a high-ranking positioon within the Cybertronian Empire in exchange for leading the Cybertronians to the Autobot and Decepticon bases.
Jhiaxus and his fleet attacked the Autobot and Decepticon bases on Earth. In order to bring a swift end to the conflict, Jhiaxus called for reinforcement to come to Earth. However, Starscream betrayed Jhiaxus and took control of the Decepticon ship Warworld, which he used to decimate the Cybertronian fleet. Angered, Jhiaxus ordered his troops to attack the Warworld, though this only resulted in more lost troops.
As the Swarm entered the battle, Jhiaxus's subordinates pleaded with him to order a retreat, but Jhiaxus would not listen, believing the Swarm to be a trick by the Autobots. However, the rest of Jhiaxus's crew went against his orders and left the Twilight in escape pods.
When Optimus boarded the ship to propose a truce, Jhiaxus brutally attacked the Autobot, blaming him for all that had happened. However, the Swarm also entered the ship and consumed Jhiaxus.
Rook later reported to Liege Maximo that Jhiaxus was presumed dead.