Egghead’s arc is becoming more and more surprising each volume that passes, since during the message that Vegapunk is giving we are given to know a great number of secrets that surround the series, such as the existence of ancient weapons.
In the last chapter of the One Piece manga we see how Vegapunk continues to transmit his message throughout the entire world to reveal the events that happened during the void century, events for which Joyboy and the World Government ended up facing each other in a battle which completely changed the geography of the planet.
He revealed that due to ancient weapons, especially Uranuswas that the sea level rose two hundred meters worldwide, thus changing the geography of this, revealing that It was not a natural disaster.
Also, on the cover of the One Piece Chapter 472a is shared image which would be key to understanding the origin of these weapons:
This confirms that Uranus was the weapon used to destroy Luluisa and I know that he is now in the hands of the World Government. Thus giving reason to many fan theories that said that this ancient weapon had been used for the destruction of the kingdom of Luluisa.
Via: Wiki One Piece
