I'm calling it now that Oscar Heimdall (or Lewis I guess) is actually the son of the lady that Noah saw in the abandoned palace (he called her a "ghost", he told it to Cesar around when he was deciding not to fight for the throne) and either the emperor or one of the emperor's brothers. His eyes and hair fit as far as appearances go, and he "came from the imperial palace" before being taken in by the Parlams. Plus he was interested in Canarias opinion on the sibling bloodbath caused by the fight for power. Only question now is whether he'll fight for justice or revenge.