Introduction
The One Piece Ancient Weapons are the single biggest ticking time bomb in the entire series, and right now, one of them has already gone off. Here at Shonen Vortex, we’ve been tracking every Poneglyph clue since the Egghead arc first confirmed Uranus was real, and this breakdown pulls together the power, the wielder, the fallout, and the last known sighting of all three weapons in one place, something the current top results split across five different pages. As of the latest Elbaf arc chapters, the fandom is split on whether the World Government already fired the first shot of the final war.
Table of Contents
- What Are the One Piece Ancient Weapons?
- Pluton: The Weapon Buried Under Wano
- Poseidon: Shirahoshi and the Sea Kings
- Uranus: The Weapon That’s Already Been Used
- One Piece Ancient Weapons Comparison Table
- Our Take: The Detail Everyone Keeps Skipping
- Why Elbaf Changes Everything
- FAQs
What Are the One Piece Ancient Weapons?
The One Piece Ancient Weapons are three world-ending powers forged during the Void Century, roughly 800 to 900 years before the current story. Kozuki Sukiyaki confirmed their names to Nico Robin as Pluton, Poseidon, and Uranus. Whoever controls all three could reportedly reshape or erase the entire world order, which is exactly why the World Government has spent centuries hunting them.
Quick facts on the One Piece Ancient Weapons:
- Named after Greek gods: underworld, sea, and sky
- Referenced across multiple Poneglyphs from the Void Century
- Pluton is a physical warship, the other two are not machines
- Only one has been confirmed active in the current timeline
- Tied directly to Joy Boy’s unfinished promise
- The Five Elders have buried their existence for 800 years
Pluton: The Weapon Buried Under Wano
Pluton is the only Ancient Weapon that’s an actual vessel. According to the blueprints Tom passed down to Franky, it’s a warship capable of leveling an entire island in a single attack. Sukiyaki revealed to Robin that the real Pluton is sitting beneath the submerged ruins under Wano, sealed until the country’s borders finally open.
Who can wield Pluton? The blueprints alone gave Franky enough knowledge to build the Franky Shogun, but the actual ship answers to whoever controls Wano’s ancient seal, which currently points toward the Kozuki bloodline.
If Pluton is unleashed carelessly, the consequence is blunt: entire islands stop existing. That’s not theory, that’s the literal design brief Tom left behind. Last known location: buried beneath Wano. Last confirmed sighting: never seen active, only referenced through blueprints and dialogue.
Poseidon: Shirahoshi and the Sea Kings
Poseidon isn’t a machine at all. It’s a living title that manifests once every few hundred years in a mermaid princess, and right now that title belongs to Princess Shirahoshi. Her power lets her command the Sea Kings, giant sea monsters strong enough to wreck entire naval fleets without a fight.
That’s what makes Poseidon terrifying in the wrong hands. Whoever controls Shirahoshi controls the ocean’s apex predators. Caribou already knows her identity and has since joined the Blackbeard Pirates, which means Blackbeard is likely one step from weaponizing her directly.
Last known location: Fish-Man Island, Ryugu Palace. Last known sighting: alive and unguarded outside the Straw Hats’ direct protection, which is exactly the kind of cliffhanger this arc has been building toward.
But here’s the real question: was Shirahoshi’s safety this whole time luck, or is Luffy already circling back for her?
Uranus: The Weapon That’s Already Been Used
Uranus is the one that changes the entire conversation, because it’s the only Ancient Weapon we’ve likely already watched go off. During the Levely, Imu ordered the total destruction of the Lulusia Kingdom. Sabo described an unnatural black shape above the clouds moments before the attack, and Emperio Ivankov speculated it was an Ancient Weapon on the spot.
Per the dominant fan theory that’s taken over the community post-Egghead, that attack came from Mary Geoise itself, fired from Imu’s throne, and it’s powered by Vegapunk’s Mother Flame research. If that theory holds, Uranus isn’t buried or hidden. It’s already active, and it’s already been fired once on a sovereign kingdom with zero warning.
Manga readers will fight us on this, but the naming pattern alone (underworld, sea, sky) makes Uranus’s sky-based nature almost impossible to argue against at this point.
Last known location: Mary Geoise, allegedly in Imu’s possession. Last known sighting: the Lulusia Kingdom’s destruction, the single deadliest confirmed use of any One Piece Ancient Weapon so far.
One Piece Ancient Weapons Comparison Table
| Weapon | Type | Wielder | Consequence if Loose | Last Seen | Last Location |
|---|---|---|---|---|---|
| Pluton | Warship | Kozuki bloodline (theorized) | Islands erased in one hit | Never activated on-page | Buried under Wano |
| Poseidon | Living title | Princess Shirahoshi | Entire fleets destroyed via Sea Kings | Alive, unguarded post-Egghead | Fish-Man Island |
| Uranus | Sky-based force | Imu (theorized) | Kingdom-level erasure from above | Lulusia Kingdom’s destruction | Mary Geoise |
Our Take: The Detail Everyone Keeps Skipping
Re-watching this arc, the detail most people skip is that Oda never confirmed Uranus’s shape or even that it’s a single object. Every other Ancient Weapon breakdown treats Uranus like it’s just “the mystery one” and moves on. But the Mother Flame connection means Uranus might not be a weapon that gets found, it’s a weapon that gets built. That reframes the entire endgame: the World Government isn’t hunting for Uranus like Blackbeard hunts Poseidon. They may have already manufactured it.
That single distinction is the biggest information gap in every current ranking of One Piece’s strongest players, and it’s the reason the “three weapons, three hunts” framing most articles use doesn’t actually hold up anymore.
Why Elbaf Changes Everything Right Now
This week’s chapters in the Elbaf arc matter here for a reason most recap sites miss: Loki and the giants carry their own Void Century ties, and Imu’s growing presence in the background of Elbaf chapters lines up directly with the Uranus theory. If Loki’s devil fruit or his hammer Ragnir connects back to the same Void Century tech that built the Ancient Weapons, the Loki vs Imu collision everyone’s predicting stops being a side plot and becomes the actual Ancient Weapons endgame.
Trending across fan forums this week: whether Loki’s backstory in Elbaf was a punishment for getting too close to one of the three weapons centuries ago.
FAQs
- What are the three Ancient Weapons in One Piece?
Pluton, Poseidon, and Uranus. Pluton is a warship buried under Wano, Poseidon is the living power currently held by Princess Shirahoshi, and Uranus is the sky-based force believed responsible for destroying the Lulusia Kingdom. - Who controls Uranus right now?
The dominant fan theory, backed by the Lulusia attack and Vegapunk’s Mother Flame research, points to Imu operating Uranus from Mary Geoise, though Oda hasn’t confirmed this directly on-page yet. - Is Shirahoshi in danger because of Poseidon?
Yes. Caribou already knows her identity and reports to Blackbeard, meaning the Blackbeard Pirates are likely aware Poseidon is a person, not an object, putting her at direct risk. - Can all three One Piece Ancient Weapons be used together?
The story hasn’t shown this yet, but multiple Poneglyph references suggest Joy Boy intended to unite all three to fight back against the forces that became the World Government. - Where is Pluton located in the current story?
Sealed beneath Wano Country, according to Kozuki Sukiyaki’s confirmation to Nico Robin, and it remains inactive until Wano’s borders open.
Conclusion
The One Piece Ancient Weapons aren’t a future threat anymore. One of them already fired, one is a person who’s already exposed, and one is still buried and waiting. Our verdict: Uranus is the most dangerous of the three precisely because it’s the only one already in enemy hands. Where do you rank Pluton, Poseidon, and Uranus by threat level? Drop your tier list in the comments.
