'Origin' is a very special term, and the reason why the original Jiuzhou Great World is said to be the origin of All Heavens and Myriads of Realms is because, at the very beginning, All Heavens and Myriads of Realms was a chaos, and Innate Holy Spirits like Pangu, Nuwa, and others were all born on the only planet.
And that planet is the Jiuzhou Great World.
Later, Pangu opened the heavens and separated the earth, evolving all living beings.
And Jiuzhou Great World gradually fragmented, drifting across the universe, forming new planets.
And each star, with the passage of time, further evolved into star domains.
Finally forming the boundless universe.
And Jiuzhou Great World is the origin of life.
So it is called the "origin" of All Heavens and Myriads of Realms.
...
As the former center of Jiuzhou Great World, the Heavenly Martial Continent possessing some astounding secrets is quite normal, but what these secrets are is unknown.
