I'm pretty flexible, I've a few previous characters I can draw on or I might come up with something new.

I was thinking maybe an older knight / minor noble who was banished by the King before Janolf executed his coup; he would have been exiled for some criminal acts of middling degree - perhaps allowing certain banned substances to be traded in the Alecan city by fiddling import papers, in return for a skim of the profits - or other corruption charges. 

Basically, he wants back in but Janolf finds it easier to keep him exiled on account of the crown absorbing much of his land, entitlements and money. He will support the Queen so long as she returns his previous lands and titles... 

Something like that... think kind of jorah mormont