Interesting concept that I'm almost done laying my groundwork for, just need to deal with the people who play the game mechanics card.
Basically, my theory I'll be using is that the Kemorian gods are not giving Pureblade favors, but instead the Albarian gods give Pureblade favors when he shows respect for the Kemorian gods. Unlike the Kemorian gods and religion accoisated with, the Albarian religious system accepts that different nations are watched after by different groups of gods. These different groups of gods created alliances with each other just as they created alliances within themselves.
Through Pureblade showing respect towards the ideals of Kemorian religion by doing their sacraficial ritual, the Albarian gods beleive that this is one small step towards uniting with the Kemorian gods. In time, this will allow the Kemorian gods to reach a larger sphere of influence, and thus let their chosen Gorbesh Emperors be able to extend their own power, thus uniting the world under one large Empire.