Joyboy was the first person to unlock the powers of, "The Voice of All Things". He passed that power on to his future reincarnations (Roger and Luffy) who possessed the same qualities and properties that he did. This is tied into why people can't learn How to Be a King (they are spiritual memories tied to the platonic form of Humans: The Human Form of the Heavenly King). During the Void Century there was a different set of ruling bodies in the world of One Piece. They were, "The Human Kingdoms", and the "Non-Human Kingdoms". In the past, the Non-Human Kingdoms were the most dominant force on the planet. Their leaders were Poseidon, Pluton, and Uranus who represented three different Non-Human Kingdoms; the Minkmen, the Fishmen, and the Birdmen species. The "Sovereigns" who were referenced by the Sea Kings are the NEW reincarnations of Poseidon, Pluton, and Uranus. They have been waiting for them to awaken their powers and meet. However, the reason why they meet at all is because of one of the Human Kingdoms leaders; Joyboy. His dream was to unite all the factions of the planet and create a peaceful world. He FAILED at doing this, and this is why he left an apology to the people of the Fishmen Kingdom (he wasn't able to bring them to the surface, meaning he couldn't unite them with the other nations and they had to remain in the ocean). The Sea Kings are waiting for Luffy, the newly reincarnated Joyboy, to bring together Momonosuke (1), Princess Vivi (2), and Princess Shirahoshi (3), because they are the new reincarnations of Poseidon, Pluton, and Uranus. Before Joyboy encountered these Non-Human Kingdoms, they were constantly at war with each other. But, he taught them how to use technology to overcome obstacles they couldn't in the past (the Non-Human Kingdoms relied solely on their Natural Tools to survive so they didn't learn about technology). The Ancient Weapons -- who were given the names of the leaders -- are, actually, derived of this meeting between Human and Non-Human Kingdoms. Each Non-Human Kingdom developed a new form of technology; ancient dial technology, among other things. This technology would be based on their UNIQUE forms of Haki (Electro, Mantra, and Fishmen Karate are all involved in this). The end of the Void Century revolved around a war that took place because Joyboy's Human Kingdom was going to become more powerful than any of the other Human Kingdoms. So, the other Kingdoms plotted against him AND the powerful Non-Human Kingdoms. It's hinted that the Nefertari Family's Ancient King made a "grave mistake in the past", and I believe that's connected to the Sky God Uranus who represented the Birdmen Kingdom. He may have been deceived into working for the Human Kingdoms in order to save them from destruction at the hands of their long hated enemies, the Fishmen and the Minkmen Kingdoms. (or maybe they just threatened to wipe all of them out, individually, and they knew they couldn't do anything about it -- so they decided to just join them... it's my feeling though that someone told someone a lie at this point in time and that's what convinced Uranus not to act on behalf of the other Non-Human Kingdoms) This allowed the Nefertari Family to be considered one of the Human Kingdoms who were given political status in the future years. The reason Kobra didn't want Vivi riding on top of Pell is because -- that freedom of riding in the air is EXACTLY what causes the power of Uranus to awaken in new vessels (the Sky God). It is said Poseidon's power will either 1) destroy the world 2) shape it into a new one -- but someone will meet her and GUIDE her on the correct path. This person is Joyboy/Luffy. Luffy has already met Momonosuke, Shirahoshi, Vivi, and made an impact on all of them. The only thing left to do is awaken their powers and allow them to meet each other to create the end-game of the story. The only reason the World Government exists today in the One Piece world is because the Sovereign Leaders and Joyboy were not fighting together in the previous world war. Instead, they got attacked before they could unite as a single force. The entire story is based on that single incident. The future world war, the war that will encompass the entire globe, will involve all three of the Non-Human Kingdoms and Luffy's Pirate Crew fighting against the World Government. But this time they will win because they aren't separated anymore. --- I would like to add that I believe it's highly likely that Joyboy did not gain the power of, "The Voice of All Things" until he encountered all 3 of the Sovereign Leaders. It's almost like math in this sense. Joyboy's Kingdom = Technical Expertise, Innate Knowledge of Practical Haki Applications (engineering) Fishmen Kingdom = Innate Knowledge of the Inner Workings of the Sea Minkmen Kingdom = Innate Knowledge of the Inner Workings of the Land Birdmen Kingdom = Innate Knowledge of the Inner Workings of the Sky After encountering all of them, an exchange of information occurred. This resulted in the Non-Human Kingdoms gaining engineering ability, while Joyboy's Kingdom gained knowledge of All Things in the Sea, Land, and the Sky (on top of their knowledge of normal things). This is why the Fishmen now have Shipwrights , and the Birdmen have Carpenters . I'm not really sure about what the Minkmen got out of it just yet, though. At the very least, I don't think the Fishmen or the Birdmen gained engineering ability on their own. The Minkmen may have simply not required much, but settled with a pact to assist each other in wars. They also considered Humans to just be another form of Mink to begin with. I would like to say... this resulted in the birth of the Ancient Weapons and the technology which drives the One Piece itself. The Ancient Weapons would use the new technology combined with each Kingdoms different sets of skills while the One Piece required knowledge of all three of them. One Problem in that idea is that Poseidon is considered to just be Princess Shirahoshi, and NOT some kind of technological feat the Fishmen designed, but that could be misleading as there might very well be some kind of technological device that simply got lost during the passage of time. However, there is no evidence of that at this point. (it may have also been related to the Energy Steroids in the National Treasure known as the Tametabako Box -- but I kind of don't want to think Joyboy gave Poseidon steroids) In the past I have speculated that the One Piece is a Matter Replicator requiring molecular signatures of anything it creates -- and it can create anything like the Star Trek Replicators which use Photonic Energy. Only, in the One Piece World, Haki itself would be considered the Photonic Energy.