It is up for you two to decide the parameters of your roles in terms of whether they're royal, retainers (maybe a brother + sister pair for the eldest heir), nobles or common folk. I think considering the weight of the issues, somehow tied to the royals would be most interesting. Still, I can't make my twins (who will act as sort of this RP's hybrid of Azura and "Corrin") until I know how they'll relate to your duo since one will already be on friendly terms (depending if mine is a retainer or tutor or something). And I'll likely make my Hoshido pair as royals with one of my twins as retainer or maid...but as I said, once you can make a plan, then I can make mine. No rush though. XD