Mana is an innate force that is possessed by living beings—mortals, elves, dwarves, agins, and demihumans. It permeates the world of Aeterna, emanating from the soils to the skies. It is the very foundation of reality, acting like the substance for the creation of life. In humans, mana varies between individuals.
As mana improves with physical training, so does magic, whose source is mana. And like magic, divine power also relies on mana.
But mana is not restricted to magic and divinity.
Given the fact that mana is the foundation of life—it is also considered as a person's lifeforce.
Once mana is depleted, it could pose a threat to a being's life. As one gets older, the ability of a person to act as a reservoir for mana deteriorates. However, the use of mana to use divine power or magic could also aid in the depletion of the said energy. It could render the person be on the brink of death.