I have a specific au in mind where Ealdor is actually all thatās left of the kingdom Ealdor taken over by Essetir long ago, its rulers having run away to live as common folk when it fell. It is common knowledge that Will is the last of this line but like why tf would it matter now ya know? No kingdom also fuck royalty.
Anyways instead of going to Camelot to fulfill the prophecy of Albion with Arthur, Merlin decides to stay in Ealdor and do something himself about making a place for magic users to stay safely.
So now the entire show is just the misadventures of Merlin and Will trying to take over an entire kingdom from scratch. Meanwhile Merlin has every intention of putting Will back on the throne because the people deserve a ruler who puts them above nobility.