The so-called Primordial Deities are the most ancient forms of deities, also known as the Ancient Gods.
They were born at the very beginning of the world's creation, possessing bodies so powerful as to be unimaginable, capable of bearing the forces of the world's rules.
Thus, they were chosen by the world's consciousness, bestowed with divinity and the power of rules, becoming the first deities of this world.
However, with the rise of new gods and the proliferation of other races, these ancient beings were either hunted and slaughtered or fell into eternal slumber, becoming part of the world, using the rules they carried to complete the operation of the world's rules.
The rules carried by the Primordial Deities were rudimentary, even primitive, so their Divine Rank and Divine Duty were very indistinct. The world's consciousness assigned the rules to them merely to utilize their power to refine and improve the world's rules.