Soul

Souls (霊魂, Reikon) are the spiritual bodies that inhabit all living things and populate the Spiritual Realm. All souls, with the exception of Vhouls, are subject to Samsara or the Cycle or Reincarnation.

Composition
All Souls are composed of several parts:
 * Soul Particles - The soul material, like a gas or thin vapor. It is bound to the Shigyoku similar to an atmosphere is bound to gravity.
 * Soul Force - A force like gravity that holds the Spirit Particles to the core of the soul. This is the energy that is utilized in many attacks and abilities, and is used in weapon extensions, etc.
 * Shigyoku (尸玉) - The Corpse Jewel. It is the remainder left after a soul departs the Living World. It disintegrates over time unless methods are enacted to preserve it.

Types
Souls fall into several categories.
 * Celestials - Spirit beings which do not possess a physical body. They dwell in the upper echelons of the Spirit Planes and oversee the balances between the worlds.
 * Ochigami - Fallen spirits which were cast into Hell and have made their way into the Physical Realm.
 * Human Souls
 * Yūrei - Ghosts, or souls of departed humans which wander and haunt the earth.
 * Shiryō (死霊) -
 * Jibakurei (地縛霊) -
 * Ikiryō - Manifestation of the soul of a live person, due to either an NDE, an astral projection, or extreme emotions which can cause the soul to temporarily divide.
 * Yōkai - A class of supernatural beings which dwell on the earth. They are the Physical Realm's equivalent of Celestials.