"Quintessence is researched heavily by Somniantis Ecclesia (also known as the Church of the Dreamer).
Quintessence is separated into Positive and Negative Essentials. Positive essentials are water, wind, and earth, while Negative essentials are fire, ice, and thunder. Negative Essentials tend to be more destructive in nature than Positive Essentials. Some items can be more influenced by one Essential than the other Essentials, and so is Tuned positively or negatively toward an Essential. For example, a rock can be negatively Tuned to fire, and thus is hot to the touch. Another rock could be positively tuned toward water and thus has a cooling effect. Such imbalances occur naturally but can be induced as well. If an animal or humanoid becomes imbalanced, it can lead to sickness.
Magic is enhanced by Essentials. By calling upon the Essentials, one can severely impact the nature of their spells. Spells enhanced by Essentials are more powerful and effective, though they drain the surrounding Quintessence. Large battles are known to kill surrounding plantlife and are discouraged by all nations during war.
Quintessence forms crystals when an abundance pools up in one location. As an example, one can often find crystals of Quintessence on riverbanks or inside caves where Quintessence pools up from the surface. Quintessence crystals have also been found in our bloodstream! This explains why some battlefields often have many crystal formations in the area.
A theory held highly in Dèlue says that aging is the depleting of Quintessence over time. When one ages, their Quintessence releases into the surrounding Quintessence and eventually rejoins the mass surrounding Lumioure. In such a way, we can be reborn as another life.
Old texts refer to Quintessence as Etoil herself and we still use the term 'Etoil's tears' to refer to crystal formations of Quintessence."
SUBJECT TO CHANGE but pretty solid. Inspired heavily by Aether in Final Fantasy (14, to be specific). Quintessence is the energy that drives the world of Lumioure. The life-death cycle, magic usage, and some other important things ;) are driven by Quintessence. This all comes from a comic I want to make reality eventually.
