It is not known for sure when or how, but life appeared in the world, with a race of beings called elves. Over time this race evolved, grew and expanded around the world until a certain moment where which three other types of beings originated from the elves, three races that were called humans, draconic and orcs. The conception of these races is a mystery, some legends say that they originated from nights of pleasure with beings from another world, beings from the ends of the earth or even dragons, but these sources are uncertain, it didn't take long for conflicts due to their differences began to happen, the humans for having a low life expectation compared to the elves proliferated quickly and steadily increasing their numbers more and more, thus conquering a part of the world. The other races didn't like this numerical sovereignty over them at all, as they always considered humans as the weakest and most imperfect race. 

The year was 0.293 when the great racial war took place, thus decimating a good part of the draconian race that in smaller numbers hid in the ends of the earth in order to recover and protect themselves, the orcs also had casualties, even so they did not chicken out and conquered a part of the world to call their territory, the elves had very severe casualties, but with the help of humans they managed to survive and found their own kingdom. The victorious humans of that war conquered most of the world, even with extremely high casualties, it didn't take long for them to recover their numbers. 

Year 0999, all the kingdoms already organized with their own technologies and mystical cults, some maintaining friendly relations with the other race, others not so much, but without another big war happening, it was a time of peace and a time of great warriors. However, this peace did not last for a long time, since another type of species was discovered in the world, there is no way to know its origin, but myths say that, they originated from the hatred generated in the ancient war, they were called demons due to their appearance. extremely aggressive and its primitive way of acting. 
In the same year it is said that these demons began to attack all races, because of this these myths treat them as a force of nature in order to subjugate those who step on it. It didn't take long for another great war to break out and out of greed, and stupidity the races turned against each other in war again, now with another vector included in the war, the demons. 
The year was 0.1263, it had been 264 years since the war raged between the races, until then the longest war that has been reported, the great nations realizing the stupidity that came from prejudice and anger for each other, they established an agreement of peace and unity among themselves in order to preserve their own races and unite against the demons, which until then has been destroying all races equally, getting stronger and evolving, getting smarter and more powerful, it is said that these beings had a capacity for evolution and learning very quickly. 

In some year subsequent to 0.1263, a historical figure who is said to have been the founder of the cult, years later called INTRA CARNEM, Melve Merlin an extremely powerful alchemist called by all as the great arch-mage made the discovery that would lead to victory against the vile creatures called demons, Melve Merlin discovered the driving force of demons a kind of power that he dubbed the Source of Chaos, using this source Merlin made several alchemical experiments, thus creating some weapons from fragments of chaos, while 10 weapons were made, later dubbed Treasures of Chaos, he also created creatures that could be used as an army, thus saving the lives of several members of all races. However, these creatures created from this source of chaos were as primitive as demons, they were not as strong as them, but they were easy to reproduce, thus making a large amount that would take care of a few demons. Merlin then succeeded in his experiment where he managed to take rational control of his creatures, it is not known what methods he used, but it led to success. 

Year 0.1282, finally a great victory by the united nations against the demons, Melve Merlin with his creation dubbed by him as daemones venatores (demon hunters) that over time became known only as venatores (hunters) gave the great victory to the nations. 

At year 0.1282, the great year in which life won over death, came the year that historians place as current years, being more precise in 1.0073, where the cult that was said to have originated by Melve Merlin INTRA CARNEM begins to worship a goddess called Shiroi and demonize another entity called Kuroi which was said to be responsible for the plague that almost destroyed the world, the demons. There are no records of these deities or how the cult took part in their existence, it is only known that from that year they were real in the world and non-believers would be hunted to death using the venators to be their scourges. 

Year 10983, the influence of the cult INTRA CARNEM dominates part of the world, thus making it divided into two beliefs, the believers in the forces of light and goodness, Shiroi or those who believe in the forces of darkness and death, Kuroi. In this same year Melve Merlin dies, it is not said how or why he lived so long since he was a human. With Merlin's death the secret of how to control the creatures called venators dies with him, what follows is the world as we know it today, kingdoms separated by races and beliefs in two opposing gods, divided by social, racial and religious prejudices. 
The last most famous historical event that is known was the extermination of a clan called Obake by the INTRA CARNEM cult, apparently this clan were somehow derived from demons, as if somehow demons had evolved to the point of disguising their identity. real nature and strength, and above all to obtain a full intellect of a non-primitive race. It is said that the entire clan was exterminated thus ending such vile creatures that once almost destroyed the world. 

The year is 1.1112. 

Document signed by the wise man;

Hashira Saemma 

Aurin Village 

Cold, dark, very cold, very dark... I can’t see, just black... everything is black. 

Uhhg... these are my hands, what is this, what is going on. 

The being that lay there on a pile of ashes and bodies regains consciousness. 

Ahnn it's Akane in front of me... wait why she's crying... 

A voice in the distance cries out in warning 

“Akane, get away from him quick this is not Kaido!!!” 

The girl is still there in front of the being, in constant tears. 

That's Akai and... there are soldiers behind him, wait there are a lot of soldiers what's going on here, why does my body feel so heavy... what is this coming out of my hands and my body... 

The girl who cries there under the being asks the same question. 

“Kaido what happened here, what happened to you… what are you???” 

The being remains there inert in the girl's lap and little by little its appearance changes from something that previously put terror and tension to everyone there, to a simple boy, suddenly

all that tension and hostility that was on everyone's faces turned into doubt and astonishment, soon murmurs of several soldiers are heard. 

“Ahnn but how is this possible...” 

"I wonder if is he one of them..." 

"They don't exist anymore... that's impossible." 

Soon a very loud and alarming tone is heard from the man who commands the troops. 

“Men arrest him and take him to the kingdom, we will hold a trial today!” 

The confused boy who previously lay inert on the girl's lap gets up and looks around him contemplating only destruction and bodies, many bodies already lifeless, mostly ashes and some missing parts of limbs, the boy falls again on his knees, when he turns back and sees two bodies, an adult man and a young woman. 

Kaido then begins to cry and scream incessantly.