Era beginning/end
Mortals began to see the Atva & Kunri as more than they are, and in turn made them into something more.
With the arrival of monsters, many Atva & Kunri devoted themselves to protecting the mortals aound them, which led to larger civilizations being constructed, and them becoming leaders of those civilizations, abandoning their original purpose. However this also made mortals dependent on them, which led to them beeing trusted and loved in a way beyond understanding. Thus a new feeling, and a new power was created: faith This new energy empowered the Atva & Kunri far beyond their original capabilities, though they were still limited by the duties they were originally created for.