It's divided into a few story arcs that, in by themselves, are mostly dependent on previous inventory Fire Emblem plots: the Plegia arc is Path of Radiance (up to the Arc Villain Gangrel acquiring the exact same title as Ashnard), the Valm arc is Mystery of the Emblem or the next 50 % of Genealogy of the Holy War (Tin Tyrant top a key armed service electrical power begins attempting to conquer the environment) and the final arc is the regular.