What happens in this scenario?
So I'm not really sure how my son got a claim on the Byzantine Empire, I had been trying to get one, but only his grandmother is a Doukas, they do currently hold the throne but his mother is from a noble family in my realm.
If I take this opportunity what happens? Does my son stay as a vassal, I assume not, but he is the current heir of my empire, so if he becomes emperor of Byzantium does he become an invalid heir? I'm administrative if that's not clear. Ultimate goal is to unite with Byzantium with my family at the helm, reform Rome, and end the Schism.
Started in the earliest start date as a landless Greek orthodox adventurer and took Africa (just the kingdom title it took like 4 lifetimes to get that much of the continent) and made a sort of Bastardized Western Roman Empire (wars in the east beside Egypt are recent)