I would say that the telos Xthonos has in mind for, and the Hegemony’s dirty little secret since all their theruges can see it too, is to be the “nature behind nature and the maker of change.” I think this means humans can change a thing’s telos in a way that animals cannot. Human’s can forge a lump of metal into a sword or alternatively a plow. We know from the game the telos of these things will be different. So blood magic is not required to change a thing’s telos, but it does rely on this mechanic to function. Thus the ultimate expression of human purpose is making blood sacrifices to change the telos of things!
From my perspective the existence a visible defined purpose for everything is evidence enough of God’s existence in this world whether you like It or not. The fact that you need to give the “universe” agency in your explanation betrays this fact as well. If you want to carry on calling Xthonos “the universe” though I won’t stop you…