
I admit, this was a bit of an impulsive post thinking about all the books with a 19 y.o. human x 500+ y.o. immortal (if you like that, no judgement I personally find it overused & a bit icky), so not super thought out, but I might have to think about this more because that is a good question
I have a fae story where the advisors took over but it was because all the heirs had been sent away during the war and no one could find them, then all of the heirs return but the advisors didn’t want to give up power, so the people they loved and trusted and were the closest thing to family and the people they had fought their way to get back to were now the enemies they thought they’d escaped.
Also this kingdom didn’t have 1 ruler, they had multiple thrones for different things, all ruled by one family, so they had the Ruler of War, the Ruler of Diplomacy, the Ruler of People, and the Ruler of Magic, each of them were cousins. They also had a step below the thrones where only the heirs sat, so siblings and kids all would be a step below the throne, they were also advisors and they often had a say in everything, especially for the throne they stood to inherit.
I know! These characters came from an apocalypse story I’d written originally and I didn’t change much so it’s really cool because it’s fae in a zombie type apocalypse but then it switches into a fantasy as they make it back to their kingdom and have to rule over a dying kingdom with little training, but the people love them because they spent years in “Elsewhere” which is where the worst of everything is, so their rulers know exactly how life is for them.