In the world the story is set in, there is no magic. However, there are many Arts.

This includes Sword Arts, Literary Arts, Martial Arts, Psionic Arts, etc etc.

There are also some Arts that can be used only by a particular species or a classification of species, like, Demon Arts can only be used by Demons and Mythical Arts can only be used by mythical creatures like Dragons, Pegasus and so on.

However, none of the Arts exist without a God who they belong to.

Sword Arts belong to the sword god, Sumka.

Martial Arts belong to the martial god, Dragneel.

Psionic Arts belong to the psychic god, Raqza.

Demon Arts belong to the demon god, Zywar.

Light/Holy Arts belong to the light god, Emoliv.

And so on.

The mortals who practice these arts are basically like following a school of thought left behind by these gods.

If a god is killed, the Art dies with them. And so, everyone who has practiced that Art loses all their powers.

This is a big reason why even though not many people in the world are religious, they still believe in gods and occasionally pray to them.

That isn't all though.

If Arts are like the various courses in the college out of which you can choose, then there is something called Realms which are like the different years of studying these courses.

Basically, for every single Art, there are these 10 Realms of power that people can ascend to or descend from, depending on various factors:-

1. Base Realm - weakest

2. Advanced Realm

3. High Realm

4. Bronze Realm

5. Silver Realm

6. Gold Realm

7. Platinum Realm (Highest Mortal Realm, i.e., the peak of what a mortal can achieve)

8. Heavenly Realm (reaching this realm means immortality)

9. Demi-God/Half-God Realm

10. God Realm

[more information will be added as the story moves on]