Your challenge is this: With a POD after 1500, unite the two great "frozen wastes filled with scary barbarians"-polities of Europe: The Kingdom of Sweden and the Grand Duchy/Tsardom of Muscovy/Russia.
No points will be awarded for unstable messes that collapse in conflicts between Protestants and Orthodox Christians within a decade. (Which, realistically, is what should happen.)
None shall stand before the great Bear-Lion of the North!