Asir was flat like a disc and parted halfway through. If you looked at Asir from above it looked exactly like the Yin and Yang symbol. Their respective capital cities were the two dots of Yin and Yang.
Yang was a place where humans lived. They were respectful of principles, tolerant, peaceful and loved spiritual harmony. Everything on this side was full of light and bright colours, as well as their inhabitants. The only strange thing was that most creatures were male. Female creatures were rare and the only reason for disputes or fights here and there.
It took some time for humans of Yang to realize that there existed another way to maintain a steady reproduction rate. A spring that produced black water was a fantastical and old attraction for everyone visiting the capital. The water which the spring produced had special properties. It made childbirth possible without having to consider the gender of the one conceiving. The child that was produced through this wonderous liquid would surely be a pillar of the new generation of adults. With outstanding abilities, a superior body and magic.
The spring water was provided to everyone who came to the capital for the purpose of receiving a child.
In contrast the side of Yin was clad in purely black and other dark colours. Especially deep wine red and violet was often seen and the gras varied between blue and metallic dark green. On this side no human being could be found. Instead all kinds of mythical creatures called Yin their home.
At least Rehan would call them mythical creatures.
Among those were unicorns and dragons, fairies, elves, grotesque homunculus-like beings made of different animals and – to Rehans surprise – even dinosaurs.
Survival of the fittest was the highest principle and the word 'peace' didn't even exist as well as the meaning of 'human' and 'reproduction'. On this side the population was mainly female. Males didn't even reach a 15% and females weren't really in need of a male partner. If they wanted, they could clone themselves any time. In addition, the inhabitants of Yin lived far longer than the average human and weren't really forced to reproduce themselves and maintaining their race.
Those two sides could have lived peacefully side by side without even knowing about each other's existence. But that wasn't what the Lord of Souls needed. Peace was a kind of stasis that couldn't get the needed energy for the Lord of Souls. Only the ongoing development – especially conflicts and disputes – of every world could give him the energy to lead so many souls and present special dead souls with enough energy to fulfil his missions in progressing the main happenings in every world.
On Asir disputes found their beginning with the escape from a Quetzalcoatlus. A fox pup decided – out of distress – to set foot into the forbidden forest that was the border between Yin and Yang. Just shortly before it lost its mother to the vicious Pterosauria and because of its panic it wasn't able to make sane decisions anymore. With a big wound on its little body it crawled over the dirty ground till it collapsed on a wide clearing in the middle of the forest.
There it was found by a bold young man. This young man knew about many forest animals, including foxes since his ancestors always lived near the woods and worked as guardians and scientists. He himself went too deep into the forest and found the injured pup by chance. He took it with him and after a long way of nursing it back to health his new little friend surprised him by changing into the form of a human. Only difference was that it had no male sex organs but females. Both were relatively shocked by the other but continued to live together after getting to know each other anew.
This meeting set the foundation of every misfortune and disaster that followed afterwards.
Their children were neither part of Yin nor of Yang. They had both characteristics and couldn't control their two opposing halves. Even though they had full support from their parents they couldn't bring themselves to accept only one half. They stayed in the forest and where thus known as ghosts and watched over the borderland. Meanwhile their parents bonding began to be widely known. First because of the prestigious family their father was heir to and second because of the curious nature of their mother. Humans began to explore the other side of the forest and always got themselves into dangerous situations. Many humans died on Yin grounds or ended up as playthings for the curious and completely different Yinnians. On the other hand, some humans kidnapped little and slightly bigger Yinnians for reproductive purposes. They thought that they could use those new and mostly female life forms to find a cure to their low female birth rate. And maybe they could use those Yinnians as a kind of incubator?
Nonetheless, their actions caused the first war on Asir to happen. Many lost their lives and the war went on for many decades, painting the earth with the blood of fallen warriors. No one wanted to admit defeat or make a peace treaty, till the Ice King took over the throne on Yangs side. He was a hybrid, his father an ice dragon, his mother a holy priestess from Yang.
Two rarities of both Yin and Yang that decided to come together, wishing for new peace on Asir.
Their son, the Ice King, paved the path for a pact between Yin and Yang. Premise for this pact was that both sides could only visit the other side if they got an official magic invitation or had a special position.
The Ice King called out advantages and disadvantages which he found out after researching and tried to show every living being how to profit from one another without discrimination against each other. The negotiations took 8 years till he got the agreement of the representatives of Yin. Meanwhile their conditions reached even the most isolated places on Asir.
The clearing on which the human and the fox met for the first time was turned into a symbol for the pact and evolved into an orientation point for beings that wanted to cross the border. Exactly there, the border between black and white mixed and created a whole, which was regarded with respect by the Ice King as well as everyone else.