Three weapons were created to save or destroy the Grand Line, with nobody knowing quite what they’re for except those who hold them. The Ancient Weapons are one of One Piece’s greatest mysteries, and while much about them is still unknown, they do have some surprising theories. The three Ancient Weapons are going to come into play big time in the Final Saga of One Piece, so exactly what are they?
This article does contain spoilers for One Piece through chapter 1094. The manga is available online through Viz and MangaPlus, so read there before reading here!
What Are Ancient Weapons?
![One Piece Shirahoshi smiling down upon her subjects.](https://www.gamescooper.com/wp-content/uploads/2023/10/Sirohshi_as_posiden1-1024x580.jpg)
Relics of the Void Century made by a military force bent on taking down the Celestial Dragons. Though whether they were made by Joyboy or someone that came long before is unclear, but there are three known in existence. One only exists as a blueprint, one is a living being, and the other is still unknown at this time, but is somewhere in Wano. The World Government is constantly trying to get their hands on these weapons, and will do anything to ensure their secrecy.
Pluton
![One Piece Franky is the only one who knowns about the blueprints of puton.](https://www.gamescooper.com/wp-content/uploads/2023/10/Franky1-1024x579.jpg)
The first Ancient Weapon shown in the series, which was in a blueprint in Franky’s possession. Although Franky burns the blueprints at Enies Lobby when he finds out that’s what the World Government is after, they still exist in his mind. The Cyborg has every little detail committed to memory over the past years since Tom died, and he could build the whole thing with his eyes closed if he needs to.
Everything known about Pluton so far indicates it’s a massive warship of some king, with the capability of taking on entire countries. This could eventually take a place among the Straw Hat Grand Fleet before the final battle, and will definitely be some welcome firepower for the fight. Franky said he doesn’t want to make weapons again, but if it comes to taking down a fascist World Government, he’ll gladly construct this Ancient Weapon.
Who is Poseidon?
![One Piece Shirahoshi is confirmed to be the Poseidon Ancient weapon.](https://www.gamescooper.com/wp-content/uploads/2023/10/Sirohshi1-1024x578.jpg)
Different than Pluton by a long shot, Poseidon isn’t an Ancient Weapon so much as a periodically reoccurring weapon. Poseidon passes through the Fishman Royal Family, usually in the Mermaids of the line. In the current story, it rests with Princess Shirahoshi of the Ryugyu Kingdom. She can speak with the Sea Kings and Neptunian’s that roam the seas, and can call them to her in moments.
Poseidon and Shirahoshi share one will, but it’s going to be a huge part of Luffy fulfilling Joyboy’s promise. The Neptunian’s will most likely be the ones to pull the great ship Noah to the surface, with the entire Fishman race inside.
Uranus
![One Piece Uranus is confirmed to be in Wano when Robin talked with Hitetsu.](https://www.gamescooper.com/wp-content/uploads/2023/10/Zoro1-1024x579.jpg)
The most mysterious of the Ancient Weapons still, the only thing known about Uranus is that it’s somewhere in Wano. That leaves a lot of possibilities open of course, but it also still leaves a popular theory open. Uranus is thought to be the Ancient Weapon capable of bringing down the Red Line, destroying it to make the All Blue in the process. That said, they never say if Uranus is a weapon in the sense that Poseidon is or Pluton is. Which is to say, the Ancient Weapon Uranus could be a person instead of a real weapon.
Two distinct possibilities are at the forefront of most people’s minds. The first is Zoro, especially with his history tied to Wano. There’s also the possibility it’s one of his swords or one he will receive before the end, possibly Oden’s other sword. The other possibility is Yamato. Nobody knows who his mother is, but with his paternal side of Kaido’s strength and incredible Devil Fruit ability, plus ice powers, he could easily shatter the Red Line.
Creators of the Ancient Weapons
Every bit of lore so far points to the Ancient Weapons being built by the Lost Kingdom from the Void Century. There’s every possibility that they could be older than that, but this seems to be the most likely explanation since the World Government fears them so much. With purposes like destroying the Red Line and ending the reign of the Celestial Dragons, it’s highly likely these weapons were created by whatever kingdom Joyboy was fighting for eight hundred years ago.
The Ancient Weapons are going to be a huge part of the Final Saga, and will have some explanations coming soon. The most recent chapter of One Piece gives a glimpse back to the God Valley Incident, so everything is being uncovered slowly but surely. Eiichiro Oda has never let fans down before, and he’s not going to start now with One Piece’s Ancient Weapons being such a huge setup.