The Witchfire Trilogy
Though the nation of Ios closed its borders years ago, a small number of its people can still be found traveling among the Iron Kingdoms. Notoriously tight-lipped regarding their home, Iosans are poorly understood, and most people react to them with distrust and suspicion.
Some few of them are found roaming far and wide, searching ancient libraries and scholars on long forgotten pieces of historical lore. An even smaller number sign mercenary contracts, becoming impressively effective, but entirely uninterested mercs.