BASICS OF REIKI:
The world is not as normal as it appears.
Beneath the surface of everyday life, unseen by most, exists a constant flow of a spiritual life-force energy known as Reiki. Reiki is vital for survival and directly linked to one's vitality and stamina along with their physical, emotional, and spiritual well-being.
At the center of every being lies the Reikon—the "spiritual heart" and origin point of all Reiki.
Reiki is typically invisible to most human beings, but there exist a small group of people born with higher amounts of Reiki, which makes them sensitive to it and gives them the capacity and potential to perceive and control it.
These individuals are called Reiki Manipulators.
YUREI:
In this world, there exist spirits called Yurei.
When negative emotions such as fear, hatred, grief, or obsession accumulate and stagnate for far too long, an individual's Reiki can distort and collapse inward on itself. When this happens, it gives birth to Yurei.
Yurei can only be seen by Reiki Manipulators and typically seeks to devour the Reikon of humans and Reiki Manipulators, as it grants said Yurei with the Reiki that flows out of it.
Yurei are not natural beings. They are manifestations, or more simply distorted reflections of human emotion that have been given form. Because of this, no two Yurei are exactly alike. Some are mindless and driven by their instincts, while on more rare occasions, some can display intelligence, speech, and even grow ideologies and beliefs.
The stronger the emotional origin, the more complex and dangerous the Yurei becomes.
EXORCISTS:
To combat Yurei and defend humanity, Reiki Manipulators are often trained as Exorcists.
Exorcists are not soldiers in the traditional sense. They are specialists who operate in secrecy to eliminate and neutralize Yurei before the wider populace become aware of their existence.
The bare minimum requirement for becoming a Exorcist is being able to perceive Reiki and Yurei. To become a traditionally proper Exorcist, it is necessary one learn and be able to control their Reiki and use a Ketsugojin of some sort.
Each Ketsugojin is different. Some manipulate or project elements such as fire or water. Other enhance the body or alter the environment. No two abilities are exactly the same, and each reflects the individual's nature, personality, and subconscious.
Exorcists operate under strict limitations and rules, like:
• They must avoid exposing the existence of Yurei, Reiki, and Exorcists to the public.
• They must minimize collateral damage.
• And above all else, they must survive.
Because even despite their supernatural abilities, Exorcists are still only flesh and blood.