(To simplify it, the Void is the universe, the Endless Abyss is a galaxy, and the Salvador Realm is a planet. Iridian is a kingdom located in the realm of Salvador. The only way to travel to other planets is to ascend beyond the Heavens, which is only doable by a Supreme or Eternal rated existence.)
How was the Endless Abyss created? To answer your question, it all started in the Void. When two supreme gods clashed, the collision created a massive black hole. This black hole absorbed the energy around it and exploded, forming a new "galaxy." This galaxy was named the Endless Abyss, due to the hundreds of realms located inside.
Inside the abyss, all realms had foundations. Some of these foundations housed special types of "essence". Most realms didn't have essence. There are only two types of essence known to history. Cursed Essence and Magic Essence. When Salvador was formed, it had a foundation that produced a special type of essence. This was known as magic essence. Magic essence can merge with humans, allowing them to use the magic essence in their body to use magic. Your magic power is said to be linked with how strong the essence is. Without magic essence, you cannot use magic. There are millions of magic powers. Magic essence cannot be used by animals. The only way animals can gain power is if they absorb Cursed Essence. However, in turn they turn into Cursed Beings, which Eternal Gods can control.
The existence rating is a list that rates how powerful one is. It starts out in order from least strongest to most. They're two existence lists, one for pure beings and one for cursed beings:
Pure Being Existence Ratings:
Regular - Gray
Unique - Blue
Exalted - Purple
Peerless - Red
Supreme - Yellow
Cursed Being Existence Ratings:
Inferior
Third-rate
Second-rate
First-rate
Eternal
In the magic association, you can get your color appraised. Using an orb, they place the tester's hand on it in order to measure their total strength. Once the hand is placed on the orb, a color will appear and the orb will glow. It is the most efficient way to find your existence rating. According to the color's brightness, you can tell what stage you are in. They're 3 stages. Early, Middle, and Peak. They're no colors for cursed beings, since they cannot be appraised like Pure Beings. In order to assess the rating and stage of a Cursed Being, one must stand next to the Deathly Aura of one. According to how powerful the aura is, one can guess the rating.
Regulars/Inferiors are beings that possess power that if measured by destructive damage, can crush a car with its maximum strength.
Unique's/Third-rates have strength that at maximum, can destroy houses. They normally live longer than Regulars by a few years.
Exalted Beings/Second-rates can destroy whole buildings as big as an apartment complex while using their full power. They normally have the same lifespan as Unique's.
Peerless Beings/First-rates can devastate an entire kingdom with their maximum power. They live at least double the lifespan of Regulars.
Supreme/Eternal Beings possess the power to destroy entire worlds at their best. They are so strong that they are able to ascend the Heavens. By ascending the Heavens, you can travel to different galaxies and worlds. A huge gap of power separates Peerless Beings from Supreme Beings. The same goes with First-rates and Eternal Beings. Supreme and Eternal Beings are immortal to age, so they cannot die to it. However, they can still be killed.
The kingdom of Iridian looked like Hong Kong. With many aspiring to become magic hunters, buildings were made to create guilds that housed these hunters. As a result, many towering skyscrapers could be seen throughout the inner parts of Iridian. Huge academies could also be seen in their own plots of land. On the outer parts, houses could be seen everywhere. Most of the people lived on the outer parts. Beyond that are lands conquered by Cursed Beings. Cursed Beings can't conquer the inner and outer parts of Iridian because of the numerous magic hunters. The sky is made up of the light and dark element, resulting in day and night like Earth. In order to surpass the sky, you would need to be a Supreme/Eternal existence rating. This is because the elements in the sky are extremely powerful, and without sufficient strength, one would instantly die when making contact with them.
The classes in the Magic Combat Facility go from rank F to rank S.