i just wanna pitch in since its the best thing to do but the way i see it. the Elibian legend might be part of the radiant dawn chronology as Radiant dawn would be the future. and ike might be the great grandson of Roy/Illina. having a pure blue-hair present with all the lords, its safe to assume that Ike not being treated a "Lord" would mean only because his great grandmother Illina was never a lord and so was roy. Illina was a mage and roy have a unique class on himself. if we want to dig deeper, because thracia 776 and genealogy takes place right next to each other having the same world(maybe at the same time right before seliph's rebellion), Seliph and Leif being cousins and all, might have spread their genes elsewhere but causes their holy blood to thin out. and we all know the elibian legend of the 7 heroes wielding legendary weapons right. it could be the world of FE 4 and 5 was the first world before it became elibe. im assuming that because FE awakening was Archanea before it become what it is now as evident with the existence of marth's legendary falcion but not gaiden's falcion which should have been the same archanea