While CoP and ToAU may at first seem unrelated, there is in fact a hidden link between the two. In the process of forming a bond with our Adventuring Fellows, we learn of two mirrors, two entities in conflict with another, and a revelation concerning the Divinity of Darkness.
This NPC Fellowship storyline directly relates to the Treasures of Aht Urhgan missions involving Odin and Alexander, as the mirrors are of near eastern origin and are tied to the "Age of Judgment" or "Ragnarok". It also ties into the Chains of Promathia missions pertaining to the "Dark Divinity" (specifically in Chapter 5, at the Bearclaw Pinnacle), and the Mithra Tracker quests "Tuning In" and "Tuning Out". Based on these various sources, I am convinced that Odin is indeed the Dark Divinity.
This video is a compilation of all cutscenes from the NPC Adventuring Fellow quests:
Girl in the Looking Glass
Watch Fellowship Quests