Our expedition was supposed to have been an allied effortaru, but not one of us was interested in the fate of the other nations. In our hasty-waste to outdo each other, we failed to see the heart of the mattaru.
Iru-Kuiru is a non-playable Tarutaru white mage from Final Fantasy XI. He was minister of the Federation of Windurst's Rhinostery ten years before the Crystal War. He was also a member of the fateful Multinational Expedition to the Northlands. His pupil, Rukususu, continues to investigate his work in the present day.
Iru-Kuiru generated controversy by suggesting that Windurst's founders had not been led to Sarutabaruta by a star, as their history told, but by a more advanced civilization. His colleagues preferred to think that celestial guidance had not only built the Federation but also continued to protect it in their time. Their disapproval did not dull Iru-Kuiru's interest in the ancient Zilart and Kuluu, however.
The Republic of Bastok approached Windurst to propose a survey of Fei'Yin, a notable Zilart ruin and valuable area for study. Iru-Kuiru joined the expedition and hired Yow Rabntah, a wayfaring Mithra ranger, to accompany him to Quon. There they joined with Francmage M Mistalle, a San d'Orian knight, and three Mythril Musketeers: the warrior Ulrich, the monk Cornelia, and the swordsman Raogrimm.
The expedition found Fei'Yin swarming with ghosts and strange machines. Although the site proved valuable to Iru-Kuiru's research, the party failed to achieve its mission to investigate the power slumbering beneath the ruins. Having given up on the city, they ventured west to see what might lie in Xarcabard.
As Iru-Kuiru and Rabntah debated with Francmage about whether this detour was worthwhile they were approached by a frantic Ulrich. He claimed that the Musketeers had been attacked by fiends and that Raogrimm and Cornelia had fallen into a crevice. They hurried to the scene but found no trace of their lost allies. Iru-Kuiru believed there were more places to look but his companions elected to cut their losses and withdraw.
The expedition disbanded and its members returned to their respective homelands. Shortly after Iru-Kuiru returned to Windurst he was banished from the Rhinostery for unspecified reasons. Inspired by something he'd seen in Fei'Yin, he put the Federation behind him and journeyed south to Elshimo.
Alone in the jungle, Iru-Kuiru tempted fate by exploring the Temple of Uggalepih, a Tonberry-infested ruin. It was not the knives of these diminutive Beastmen that threatened him, however. A massive demon, the Shadow Lord, appeared before the wandering mage. Born from Raogrimm's rage and thirsty for vengeance against those who had left the swordsman to die in Xarcabard, the Shadow Lord murdered Iru-Kuiru.
Thirty years pass but Iru-Kuiru does not find peace in death. He drifts incorporeally between Vana'diel and the dreamworld of Dynamis. Attempting to exert some influence on the living, he nudges his former student, Rukususu, to the place where he had died. She learns that Iru-Kuiru had been right about Windurst, it had indeed been founded with assistance from the Kuluu rather than a star, but chooses not to publicize her findings.
Around this time a threat begins to emerge in the dreamworld. Though the Shadow Lord had been vanquished and Raogrimm freed from his rage, a piece of the demon had taken hold in Dynamis and grown to enormous strength. The spirit of Raogrimm, separated from this new Shadow Lord but being pulled toward it, searches for aid among those that had defeated his earthly body. When he is unable to rally such champions himself the ghosts of the other expedition members take up the cause in his place.
Though Iru-Kuiru had been murdered by the monster that Raogrimm became, he accepts responsibility for allowing the circumstances that created the Shadow Lord. To atone he guides the Adventurer through the dreamworld's representation of Windurst on their road to destroy Raogrimm's dark counterpart.
When this "Dynamis Lord" falls, the true ruler of that plane, Diabolos, speaks to Raogrimm. A divided soul cannot leave the dreamworld and the swordsman is inevitably separated from his raging alter ego. Diabolos therefore assigns him to stand watch over Dynamis until a day when hatred no longer exists.
The other members of the expedition surprise Raogrimm by joining in this task. He had not expected their company after taking their lives with his own hands. For his part, Iru-Kuiru is too excited at the prospect of studying Diabolos to be held back. The Tarutaru therefore commits to eternal vigilance alongside his former companions.