| Free of Spoilers: This page contains no spoilers from the events of the games. |
Feel free to read it as much as you please.
Souls are a fundamental form of energy that allows for intelligent life in the continent. All living beings that are sentient and rational possess a Soul. In appearance, souls are small glowing and intangible orbs, and they can't be touched or manipulated by any means by mortals. All souls originate from the Creator God Ludo-Rathowm and they are the source of all 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 the past the Gods experimented by creating multi-souled beings, as they were trying to create a magnific race, which resulted in the Dragons, but because they ended up being too perfect to amuse Ludo-Rathowm the idea was ultimately discarded. However the Demon King, or more specifically the Demonic Blood Pool, is an entity composed by a large number of Souls. Dark Lords gain a number of those Souls upon their transformation, which alters it into what is known as a Demonic Blood Soul. Dark Lords repeat a similar process upon creating Apostles, which is why the host is weakened upon doing so.
In essence a 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 that initially contains only 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 traits ever since the birth takes place.
When the mortal dies, the soul is taken to Hell so that they can 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 through a process 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, the information of high-class souls have to first be 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 directly responsible for the foundation of the Kingdom of Zeth, a large nation in the continent with a big influence on the world.
All souls were originally part of Ludo-Rathowm's body, which was, prior to the continent's creation, made up of a total of 10 billion souls. When he decided to create his world, he used his own body mass, utilizing 1 billion souls to craft The Continent and the Four Holy Beasts. After that, he employed another billion to create the Three Supreme Gods, albeit due to his careless nature part of it ended up as a wasted left-over that resulted in the birth of Devil King Rathowm.
Following the world's creation, the establishment of several living beings in his world like the Protagonist Race and Monsters, the creation of more Gods and through some other baselines for the world's rules like the Reincarnation Cycle, a large number of souls was utilized, with Ludo-Rathowm's body at present-day consisting of a total of 5 billion souls.
On normal circumstances, between 92 and 98% of the population that makes up the numbers of the Protagonist Race are alive, dying and getting replaced in birth through the natural events of the mortals' lifestyle. In times of great conflicts, a larger number of people die and the mortality rate surpasses the birth rate, making the pool of souls dedicated to the Protagonist Race smaller, which is how the Hero System's modes of power are gauged. In some extreme cases, Supreme God Roven-Pan may transplant some souls from the reserved "Stock" pool. The stock is also the secret for the Hero System's immortality, which has a system in place that automatically replaces the Hero's soul with one from the Stock pool in case they die.
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 disappear 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.
Gods and Devils are the only ones capable of touching and manipulating souls, however, soul pollution drastically alters their composition, making the conditions to do so more complicated. A raw Soul from Ludo-Rathowm's body, pure and with 0% of pollution, cannot be grasped by a Devil, but the more polluted it is the more tangible it becomes to them, while for Gods it's the opposite. Souls that reached 100% pollution become invisible and ungraspable to the Gods, which is why they can't collect them.
Being the Creator God's opposite, the Devil King Rathowm's body is composed of Souls of 100% pollution. Just like Gods need to cleanse a Soul of all pollution so that it becomes compatible with Ludo-Rathowm, Devils do the opposite in order to add it to the Devil King's body. The more polluted a Soul is in life, the more valuable it is for a Devil, and souls with 100% pollution are considered a super rare treasure.
- 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 instinct. The only exception of soul-less creatures that do are Youkai, who are born from emotion and with their existence 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.