The Allagan Runestones were a set of rewards sometimes earned for the completion of specific Faction Levequests. After obtaining these Unique and Untradable items from their respective reward chests, they could be traded to Rowena, along with specific materials, for the Harlequin, Templar, and Buccaneer sets of attire.
Almost nothing is known of the runestones' origin. The exact time of their creation is obscure, but likely occurred during the 3rd Astral Era, when the Allagan Empire was at its peak. Their purpose is even more mysterious, eluding perhaps all of Eorzea but for a single man: an anonymous Ishgardian noble who has tasked Rowena with collecting the lost pieces. Whatever their use, the aristocrat is willing to part with items of extraordinary value in exchange for the seemingly useless stones; in particular, three sets of antique armor exceptional in quality.