Well, a thought occured to me today (it happens a lot) that maybe Robin,Mark, and Kris are all related by blood. Basically, FE7's tactician Mark's children lead to FE12's my unit Kris, whose Children lead to FE13's Robin.
My only real basis for this theroy is Lyn's DLC convo in Smash Bretheren 3.Obvious reference is obvious. So if there is any real contradictions here, I would like to know.
Also, I know Elibe and Archenea are possibly differnt worlds, but Awakening proved travel between worlds is possible in FE.