What Are the Ancient Weapons in One Piece? (& What Are Their Powers?)

What Are the Ancient Weapons in One Piece? (& What Are Their Powers?)

The Ancient Weapons, of which there are three, are weapons capable of destroying the world and which the government and certain pirates seek to seize for their own ends. Their names are Pluton, Poseidon and Uranus. Since the Ancient Weapons have a connection to the Void Century, the World Government tries to stop people from seeking them out as they fear that knowledge of these weapons could lead to a World War.

However, that didn’t stop members of the World Government, like Spandam and the former Shichibukai Crocodile, from trying to get one of the weapons for themselves. Even without knowing about the Void Century, their power has been known to interest casual observers (as was the case with Vander Decken IX who took an interest in Shirahoshi, otherwise known as the ancient weapon Poseidon).

In this article, we are going to present the Ancient Weapons from One Piece to you and tell you what they, as well as what their powers and abilities are. This article is going to serve as a guide and introduction to the Ancient Weapons in One Piece. We are not going to provide you with too many details here, but there are going to be some spoilers so if you don’t want to know the details before actually reaching the desired plot moment, be careful how you approach the article.

What are the Ancient Weapons in One Piece?

The Ancient weapons in One Piece are the most dangerous weapons of mass destruction in the world that were built during the Void Century. There are only three: Pluton, Poseidon and Uranus. These weapons are not limited only to inanimate things like normal weapons, but can also be latent in any being, that is, it is just a special ability.

The Ancient Weapons are the argument used by the World Government to ban Void Century research, as they fear that knowledge of these weapons could result in a world war. However, this hasn’t stopped some members of the World Government, most notably Spandam and the former Sea Warrior Crocodile, from trying to claim one for themselves. Some even unaware of the Void Century have been drawn to its power, as was the case with Vander Decken IX and his interest in Shirahoshi, also known as Poseidon.


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Not much is known about them collectively, and since we are going to analyze each of these weapons individually in separate articles, we won’t be giving you too many details here in this article. They are powerful and they are mysterious, which is why they are so important for the whole One Piece lore. In act, the Ancient Weapons are basically the most powerful weapons in the whole One Piece lore, which speaks enough about their relevance for the plot.

Their overall role in the story remains to be seen, though, as Oda hasn’t revealed too much about them, nor have they been put to use at the moment. But, the danger they pose for the world speaks enough about their importance.

What are the powers of the Ancient Weapons in One Piece?

In this section, we are going to give you some details on the Ancient Weapons and their known powers and abilities. We won’t be giving you too many details, as you will be able to read about each of them individually in separate articles. As we’ve stated, some spoilers are going to be present in the paragraphs below, but don’t expect too many revelations at this point; the individual articles are going to serve that purpose.


Although Pluton has yet to physically appear in the story, it has been referred to as an ancient ship capable of massive damage. It was built on Water 7 sometime during the Void Century and the carpenters on that island kept the plans safe as a safety measure, in case Pluton fell into the wrong hands, luckily the ship was lost to history before then. for that to happen.

The blueprints were passed down from generation to generation, and ten years before the main story, it came into the hands of the fish-man carpenter, Tom, of the Tom’s Workers. At this point, Spandam sought them out in order to acquire the plans so they could use Pluton to end the Great Age of Pirates.

Tom refused the request, and soon after handed them over to his apprentice Iceburg, who passed them on to his other apprentice, Cutty Flam, aka Franky, five years later in order to better hide them. When Franky was captured by the World Government, he kept the blueprints hidden within his own body, until he realized that Nico Robin, the only person alive who could read the poneglyphs and subsequently revive the Ancient Weapons, had no intention of doing so or using that power to destroy the world, but subsequently burned the plans.


Although the details are not known, it is known that Pluton is somewhere in Wano Country and that this was what the Arabasta Poneglyph indicated. It’s supposed to be a big warship. Not much else is known about it. When they first saw the plans, Franky, Iceburg and then Kaku and Rob Lucci looked shocked, with Franky and Iceburg wondering how a ship like Pluton could be built in the first place.

Its power was as dangerous as other weapons like Uranus and Poseidon, though the exact details of their abilities remain unknown. It is said that Pluton is capable of destroying entire islands. Whoever had the weapon under their control had the potential to take over the world and in the wrong hands would be extremely dangerous. Likewise, Pluton also had the ability to wreak so much havoc in the world.

Additionally, since the plans persisted even after the ship was built, anyone with the ship’s plans would have the ability to build a fleet of ships with the same destructive capabilities as Pluton. The blueprints had been kept as a safety measure to bring Pluton back into existence should the world need it to fight weapons, including the original battleship itself. At this point, however, the blueprints that were used to create it are now destroyed while Pluton itself is still asleep.


Poseidon was first mentioned when Nico Robin read Skypiea’s poneglyph. Recently, the king of the Ryugu Kingdom, Neptune, revealed that Poseidon is located on Fish-Man Island itself. This weapon is not an object, but a hereditary ability that only some female members of the royal family of Fish-Man Island develop every 100 years according to Neptune himself.

A power inherited and awakened by Princess Shirahoshi, which consists of being able to summon, communicate and control the sea kings at will. The only mermaid princess who has also possessed this ability is Princess Poseidon, who lived in the Void Century. Instead of being an inanimate object like the usual weapons (except for weapons attached to Devil Fruits), Poseidon is a mermaid who belongs to the royal bloodline of the Ryugu Kingdom.

After her death, her name was treated as a title given to a mermaid who was born into the royal family and had the same power that she possessed in life. In the present day, Shirahoshi has inherited Poseidon’s power and name from her. Any possessor of this ability is called Mermaid Princess. Poseidon has the power to communicate with and control sea kings, an ability that even the mightiest of merfolk cannot use.

This is considered to be a powerful weapon due to the potential of Sea Kings, whose power is such that they can destroy and sink islands with ease, and controlling that force is considered to be one of the most fearsome abilities in the entire world. While this power, guided by the power of love, can save thousands of lives, with bad intentions, it can sink everything into the ocean, and might even have the ability to “destroy the world.”

The sea kings refer to Poseidon as their “queen”. The current Mermaid Princess, Shirahoshi, has shown that her powers awoke at the young age of six, having no control over her own abilities and unconsciously summoning sea kings when she cried out loud, something that was feared in the entire Fish-Man Island. Ten years later, during the battle against the New Fish-Man Pirates, Shirahoshi fully awakened her ability and apparently gained control of it.


Uranus was mentioned by King Neptune while he was explaining to Nico Robin what the apology letter he had written on the Fish-Man Island Poneglyph meant. Nothing is currently known about Uranus, except for her name. Given the nature of Pluton and Poseidon, Uranus could easily be an animate or inanimate object.

Uranus is the only Ancient Weapon we know nothing about at the time. It exists, that much is known, but what or who it is, as well as what it can do is currently unknown. This is one of the bigger unanswered mysteries in One Piece so we expect Ida to reveal the truth behind Uranus relatively soon, as it might play a pivotal role in future events.

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