Soul

The Soul is the true essence of a living being, a blueprint of the body. It is the record of memories, feelings, emotions, reason, character, and conciousness. It also has the Will and the Vessel which contains the Essence.

Nature
Souls are an essential part of living beings. Every living being has a soul but only Mystical Species have the Will in it. The Soul is considered as the invisible command structure of the body, which is used by the Soul as a vessel to do things the Soul wills. All souls are immortal since it is an existence transcendent of the physical world and reunited with the Great Flow after the body has died. Souls are part of the World. The Soul is manifested in the physical world through the brain. Souls cannot be die or destroyed as they are part of the World itself. All Souls contains a Vessel with Essence with the bizarre exception of the Nervetii people.

Eccelsiea of Reia
Ecclesians believe that the Soul has value based on merit. The value is ranked by color with Black being the lowest, followed by White, Silver, and Gold being the highest. It is said that Olyrh Reia has the most valuable soul with the color of Gold. All humans are born with the Black Soul and they are changed frequently. To raise the ranking of the Soul, one must do good deeds or become a man of great fame and honor. Every eligible King/Emperor of Reia has the ranking of Gold as it is the most prestigious title one man can have.

Soul as a source of the Essence
There are studies suggesting the viability of converting a Soul to a source of the Essence. Maschida Purloni hypothesized this in his work "The History of the Magical Discipline" where he stated that Souls can be converted to the highest form of human energy. Neris Scarwind says that Souls through a thorough process of Metamorphosis can be transformed into Essence but he was refuted by various Metamorphic scholars that even an Essence transformed from a single matter cannot be used by humans since it is has the same harmful effects from Telesma and Keron.

Shina Muu, a Metamorphic scholar, conducted a study involving transforming a Soul into another matter. Muu says that the study failed because there is no feasible way to even visualize the Soul. The future of Soul as a source of the Essence is still unclear and even if it worked, many experts are wary of the ethics of converting Soul as Essence.