"Our souls have been torn, and our bodies forsaken."
The word 'forsaken' as thematic to primals seems to hold water. What if primal summoning requires the sacrifice of a physical body, whose soul is merged with the primal's essence?

-The Echo-using Sahagin priest becomes able to transfer his soul to a new body, but is then absorbed into Leviathan.

-The ritual foci mentioned in the Extreme primal cutscenes are made of beastmen remains, fashioned by the Ascians, and have the effect of enhancing the powers of the primal. Why should the bones of beastmen have such an effect?

-Odin's physical form is altered to resemble an adventurer who fought him before. Is his essence 'borrowing' the body of a powerful fighter who felled him?

The 2.3 story teaser image of a mysterious, silver-haired maiden was almost unanimously heralded as being that of a non-primal form of Shiva, but made me wonder, how? Is she is intended to be a physical ideal, or a sacrifice, to bring Shiva into being?