Souls

About
Souls are a fundamental form of energy that allows intelligent life in the continent. All living beings that are sentient and rational possess a Soul, with the exception of Dark Lords, whose soul was instead transformed into what is known as a Demonic Blood Soul. All souls originate from the Creator God Ludo-Rathowm and they are the source of life. The body of Ludo-Rathowm could be seen as a giant mass of souls. Mortals such as Humans, Kalars, Hannies, and Monsters are born from these souls and these procedures are overseen by the Gods. In appearance, souls are small glowing and intangible orbs, and they can't be touched or manipulated by any means by mortals. Only Gods and Devils have the ability to grasp souls.

In escence the soul is like a memory used to store data, from basic information like physical appearance to levels, skill levels, memories and personalities. The soul itself starts in a blank state filled only with randomly generated attributes like a Level Cap and the previously mentioned Skill Levels, but it is filled and updated with other information such as memories and personality ever since the birth takes place.

When the mortal dies, the soul is taken to Hell and would later return to Ludo-Rathowm. Since souls are filled with information gained from life, said information must be eliminated in order to return to Ludo-Rathowm's body. Onis in Hell, format these souls from all the raw data it possesses. The administration process is handled by Angels in the Gods Realm, done mostly in a work akin to paperwork. The highest authority in the Soul Administration Bureau is the 1st Class God Quelplan, who manages the flow of over 100 million souls and carries out her job dutifully. Within the Administration Bureau, souls are classified based on the historical influence they had during their lives. The higher the class of the soul, the more important the data within it represents, and as such, are seen as more valuable and the information of high class souls have to be first examined by Quelplan directly before getting eliminated. For instance the soul of Parsley Rig Zeth is classified as an A-Class soul due to being responsible for the foundation of the Kingdom of Zeth, a large nation in the continent with a big influence on the world.

Soul Pollution
During mortals lives their souls get polluted from negative feelings such as pain, sorrow, regret, among others. The more polluted a soul is, the more incompatible it is with the Creator God, so the Oni must also cleanse the pollution of a soul. All souls are polluted to a bigger or lesser extent in life, regardless of who it is. The average soul is around 30-50% polluted in a single lifetime. According to Crook a rule of thumb is that one's soul pollution usually shouldn't be above one's age. Soul pollution can also decrease if negative feelings corrupting that individual dissappear as well, decreasing the rate. Due to the excess of negative feelings, humans typically commit suicide upon reaching 80% pollution, though it depends on each person. In the extreme rare cases where a soul got 100% polluted, this soul can't be cleansed and goes to waste, unable to return to Ludo-Rathowm.

On the other hand those whose soul had a small amount of pollution receive straightforward and simple cleaning. On extremely rare cases, Onis might make a mistake on these undemanding souls that were cleaned and some data may remain even after getting sent away from Hell. This data could be then mixed on a soul mass that was used for reincarnation, resulting in rare cases of people being born with physical traits or memories from people that have already passed away.

Trivia

 * Technically, it is possible for a mortal to revive in the period of time that exists between the time he/she dies and before the soul is formatted by the Oni, although only top classed Gods and Devils can do such thing.
 * Creatures that lack a soul such as Insects also lack rational thoughts or personalities, and act purely on instict. The only exception of soul-less creatures that do are Youkai, who are born from emotion and with their existance tied to Orochi.
 * The Toushin Toshi series' concept of Sin may be related to Soul Pollution, including how it can be cured by a fukuman.