At the time of the Great War and the subsequent exile to Shakuras, he served aboard the carrier Koramund, eventually becoming the legendary vessel's third engineer. He considered being part of its crew a great honor.
When the Koramund was ambushed by the zerg in orbit of Vanass, Iaalu was sent to repair the damaged engines. He tried to prevent the ship from crashing into the surface of the planet below, but failed. Having survived the crash, he soon discovered that his superior, the templar Tenzaal, had sabotaged their mission to destroy the Koramund and thus prove the uselessness of the old carrier concept. He fought the mad templar for control of the dead Praetor Quordas' khaydarin amulet, and eventually prevailed.
In the process, the crystal was depleted, and Iaalu himself became the new "spark" fueling the Koramund, its flow of energy synchronizing with his heartbeat. With the rest of the crew dead, he reactivated the vessel and lifted it off the planet to return to the stars.