The Essence is the metaphysical energy or life force that can be manipulated to create what could be viewed as magic. There are different planes of existence (Realms) with varying degrees of strength (Magic), determined by their proximity to the Essence. The planes of existence in Ashes of Creation are connected across bridges created by the Essence.
The Gods & The Essence
The Gods exist on the plane of the gods, which is the most connected to the Essence. The material plane is not the highest in terms of proximity to the Essence. Verra exists in the material plane. The Void is the plane that is the furthest from being connected to the Essence. Only a small amount of essence can be found within the void.
At this time there still hasn’t been a definitive understanding of how many planes of existence there are.
Masters Of The Essence
The Gods are masters of The Essence, but they are separate from it. One didn’t create the other, but they exist together in a symbiotic form, where the gods have achieved an almost perfect manipulation of The Essence and of “lesser beings” who exist further from the Essence.
The Essence is so powerful it flows through the planes almost like a river. Soul conduits help to maintain or even exaggerate this flow. Details surrounding this have not yet been revealed but this idea is an integral component of the broader feature of the storyline in Ashes of Creation.
The Essence & The Magic System
Souls are the conduits for The Essence to travel between the different planes of existence and the Tulnar have souls and these souls act as conduits for the Essence. We are still working out the details about how The Essence and the magic system in Ashes of Creation will work from a narrative standpoint.
Shape-shifting is a form of magic manipulation. Shape-shifting is done so through the Essence by focusing on that specific type of magic.