Davy clan and the first world

This is a theory has recently popped in my head since it explains the order of events in the second world and might explain why some mysteries in the first world

BTW THIS IS A LONG THEORY POST

We all can assume that the Davy clan was the ruler of the ancient kingdom but we don't know is how they got there

Let me start with the first world part of the theory, the original Nika had an enemy which defeated him and it was the power of earth god and the serpant of fire, since DFs didn't exist in that time period it was probably some powers that spawned through the mother flame and it gave birth to powers like the Nika, the ancient weapons and nidhogger

The earth god and the serpent of fire belonged to the founder of the Davy clan, and once he got those powers and defeated the original nika he then reshaped the earth and slaughtered everyone else

The powers of the earth god was probably a mix of the gura gura no mi and another power that rocks was after (probably the serpent of fire)

Because the Davy clan had the powers of the first world which was highly advanced, they were able to rule with great power for centuries even after the first world, and that's why it's mostly known as the ancient kingdom

But once the second world started imu created DFs and cursed Davy D Jones and separated his powers in order for them to never resurface again in history, which is why imu denies the existence of Davy D Jones and his title of king of the world during his talk with rocks

During the second world era, imu first fought the Davy clan before fighting joyboy

After his loss Davy Jones became a pirate to regain his power

Which explains how joyboy was the first pirate but Davy Jones lived in the same era

TLDR; the founder of the Davy clan had the powers of the earth god and serpent of fire, he was the one who defeated the original Nika and ruled the world and his descendants ruled after him up until imu took them down