[@ShadowSunRisen] Ideally they would be an Archduke since the Mistland still lacks one. The North overall isn't that wealthy and most of your family could have gotten the axe from the Mad King leaving only the prince behind so right there is the hard times and falling from grace. Still if you really want to pull a Littlefinger go ahead. 

I would say try not to go too magical with the supernatural or at least have an OOC explanation of what's really going on (like how the "dragons" in the Dragon's Graveyard are actually dinosaur bones).

An idea I just had before posting this is that it could be the Mistland right now has no Archduke actually, the Great House having had the gall to try and say no only to get killed by the Mad King for it. The first step to power for your character could be trying to become Archduke of the Mistland.