He served under First Teron'tokal and Vorta overseer Yelgrun, who commanded a patrol sent to monitor the activities of the USS Lambda Paz, which was dispatched to the Tong Beak Nebula to verify intelligence that a Jem'Hadar breeding facility was being built on a planetoid in the nebula. Romat'ison was named second-in-command by the time that same fleet of ships confronted the Federation Alliance in the Siege of Sector 21607 following the executions of Second Ulin'talag and Third Otan'irix for insubordination. Because Romat'ison was young and inexperienced, Yelgrun decided he would have to earn a promotion to the rank of Second once the battle was won.
Romat'ison soon discovered that no breeding facility was on the planetoid. He was among the Jem'Hadar who killed Yelgrun for having deliberately lied to them. Soon afterward, Romat'ison and the rest of the crew the Jem'Hadar heavy cruiser were killed when Hasin Arnit, who had escaped the Lambda Paz after being revealed as a mole, set a collision course for the flagship. (Star Trek: Lambda Paz: " Revenge a Dish Best Served Cold")