The Soul - An immortal collection of past lives, experiences, and concentrated mana.
- The Book of Kraus states that: New souls manifest in Avalon before leaving for Eternia to mature over the course of many lifetimes and trials, to eventually return once ready. Souls forced to remain within a host that's exceeded its natural lifespan will exude depravity. A soul requires the viewpoints and experiences of many to return.
- Souls are protected by a powerful barrier that only divine magic is capable of bypassing to interact with directly.
- An angel doesn't live through multiple lives... rather, any changes in their character are gradual and permanent, unlike a human that can experience more personality development in a lifetime than an angel can in tens of thousands of years. All angels were designed with a fleshed out personality by their creator, another contrast to the creatures of Eternia that mostly learn through experience and personal freedom, starting blank as a newborn.
Essence - A single lifetime, a piece of the soul.
- An unstable essence may return to Eternia in the form of a 'spirit', a mana imprint sent from the spirit realm where the essence will remain, protected by the guardians of the realm. The imprint is linked directly to the essence and its experiences are shared. Magi capable of exorcising spirits may be employed if a spirit haunts a person or place, as they cannot be killed persay, but can be banished from a location or barred from the living realm for a number of years.
- Unlike the soul, it is possible to change or outright destroy an essence without divine magic, typically through depraved means, but only an incomplete essence that has not been sealed within the soul's barrier. For example: Assuming the person 'Cassius Artorious' is alive, his essence is vulnerable, but the essence of 'Alpheral', one of his past lives, is not vulnerable unless they've yet to move on from the spirit realm.
Mana - The fuel of the body that provides energy and can also be channelled for the use of magic if the person is capable. The soul provides this directly.
Magical Circuits - The circuitry that mana flows through, with creatures of the same species having near identical magical circuits. This varies somewhat among sub-species (Oscuri and Drakanites, for example). More is being uncovered about the magical circuits with each passing generation, and knowing it intricately is vital for things like alchemy and organism-based runewriting.
Body - The skin, flesh, and bones. A healthy body is important for casting magic effectively.