Musing on the towers more...

I think I'd honestly love if it turns out that they're actually part of a gigantic super primal that embodies Garlemald's doctrine of conquest through power (Which would explain both how they seemingly appeared out of nowhere as well as their disturbingly organic interiors).

Such an entity would be more akin to a force of nature then a proper god as it would basically be a blank slate that's driven purely by its purpose for creation, bereft of the personality primals normally are given from their worshippers.

Perhaps Zodiark isn't even the ultimate goal of Zenos and Fandaniel anymore and he's simply a means to a greater (And worse) end; to be used as fuel for a new primal.