Board Thread:General Discussion/@comment-6192846-20140111153519/@comment-6192846-20141026145655

Incarnation still applies, as it's still the embodiment of a god/spirit/abstract being made flesh. The type of magic used to incarnate them however is something akin to transmigration, not a cycle of rebirth like H&G's reincarnations.

This would also better explain Gumillia's lack of aging, as she still has the qualities of a spirit with great magical power, she's just been given the physical form of a human rather than an animal or her abstract spiritual form.