The Abyssal Leap
Otharion is the product of the same pantheon responsible for the world of Golarion, but it exists far, far away from that world. Upon its creation, Asmodeus saw the breadth of the forces arrayed against him were he to attempt to wrest control of the world, and he devised an ingenious strategy; a wager for the future of the world. Asmodeus presented the world as a mirror of Golarion; where the gods would intervene upon one, the other would be watched, but left to its own devices, free from the direct influence of its creators. Asmodeus predicted, correctly, that honor would prevent his staunchest foes from violating the terms of this wager, and that fear of reprisal would prevent the rest.
The terms, however, did not prevent Asmodeus’ underlings from intervening; as they were not part of the pantheon, they were bound by no such obligations. And so he had his loophole; a world in which he could indirectly influence entire eras. While his grip was greatly lessened with the destruction of the Demon Stones, his hand remains the only one controlling Otharion’s destiny.
It is important to note that no one in the current age is aware of this influence; to this day the gods have not broken their pact of non-interference. They are each permitted to grant spells to their followers, but (with the exception of Asmodeus) that is the extent of their touch. Mortals, as far as they are concerned, are masters of their own destinies.