Ancient Weapons Theory: Origins, Roles & Void Century Secrets

With the Final Saga now in full swing and Imu’s devastating attack on the Lulusia Kingdom still echoing through the fandom, the mystery of the Three Ancient Weapons has never felt more urgent. If this theory is correct — that the weapons are not three equals but rather “two plus one,” with origins stretching back to the Moon itself — it reframes everything from the Skypiea arc to the Void Century in a completely new light. The pieces have always been there, hidden in plain sight since Chapter 470’s lunar murals, and Japanese theorists believe they’ve finally cracked the full picture.

The Theory

The stakes here are enormous. If this theory holds, then the Ancient Weapons are not three separate inventions scattered across history — they share a common bloodline, a shared origin on the Moon, and a predetermined endgame: destroying the symbols of World Government control (the Red Line and the Calm Belt) to merge the Four Seas into one. Every arc from Alabasta to Egghead becomes a chapter in the same 10,000-year-old story.

Evidence from the Manga

1. Chapter 650 (Volume 66): Nico Robin recites the foundational text — three Ancient Weapons bearing the names of gods: Pluton, Uranus, and Poseidon. The names themselves are the first clue. “Lunaria” derives from the Latin/Italian word for “moon,” directly linking the Lunarian tribe to the Moon. Their homeland atop the Red Line was literally called the “Land of the Gods” (Chapter 1023), and before Mariejois existed, Lunarians were worshipped as deities. If Uranus carries a celestial god’s name, and the Lunarians were those gods, the weapon almost certainly originated with them.
2. Chapters 470–472 (Volume 48–49): The lunar murals discovered by Enel depict three distinct winged peoples — identified here as the Shandians, Skypieans, and Bilkans — departing the Moon aboard a large vessel due to resource depletion. The chapter subtitle for Chapter 472 reads explicitly: “The Moon City, Known as Bilka — Fleeing to the Blue Star Due to Resource Shortage.” This vessel is not just a spaceship; it is the original Ancient Weapon Uranus. The Moon People rode Uranus to the Blue Star roughly 10,000 years ago, which is precisely why it carries the title “Ancient” weapon.
3. Chapter 344 / Chapter 355 (Volumes 36–37): Iceberg reveals that Pluton is a warship built “long ago on this island” by Water Seven’s shipwrights — so powerful that master shipwright Tom called it “the worst monster in shipbuilding history.” The question the theory asks is sharp: could craftsmen of that era have designed something that world-class shipbuilders 800 years later were thunderstruck by, completely from scratch? The theory argues no — Pluton was a sea-adapted reconstruction of Uranus, which is why the two weapons share the same core capability.

📌 Key Evidence: Pluton and Uranus share one defining power — “a single shot that obliterates an entire island without a trace.” This is not a coincidence of power scaling; it is the same weapon’s DNA. The difference is their operating environment: Uranus flies (a space/sky warship), while Pluton sails the sea. The World Government possessed Uranus yet still desperately hunted Pluton’s blueprints — because without the Lunarians to fuel Uranus, they needed a version that could run on Blue Star energy.

4. Chapter 924 (Volume 92) + Chapter 240 (Volume 26): Hawkins states in Wano that “Seastone was born in this country.” Meanwhile, Pagaya explains in Skypiea that the substance Pyrobloin — found within Seastone — is carried skyward by volcanic eruptions to form Sea Clouds and Island Clouds. This creates a direct geological link: Wano’s Fujiyama volcano produced Pyrobloin, which eventually enabled the creation of Skypiea’s floating islands. The Moon People landed in ancient Jaya (geographically connected to Wano per the skull-island theory), the volcano erupted, Pyrobloin was discovered, and the sky islands were born — explaining why Jaya and Wano share ten remarkable cultural parallels.

📌 Key Evidence: Zunesha speaks in Chapter 1043: “I hear the Drums of Liberation… for the first time in 800 years… Joy Boy has returned!” Cross-reference with “Binks’ Sake”: “When the drums of dawn are heard, we’ll deliver Binks’ Sake.” The “drums of dawn” are the Drums of Liberation — meaning Binks’ Sake is a coded message about delivering the Ancient Weapons to Laugh Tale. Roger had the song but lacked Joy Boy and the weapons. Luffy now has both within reach.

5. Chapter 1085 (Volume 107): Imu directly tells Cobra: “‘D’ is the name of those who once opposed us.” Combined with Chapter 395’s revelation that a “certain great kingdom” was erased during the Void Century, and Chapter 1018’s confirmation that guards who merely spoke the name “Nika” were eliminated, the theory’s Void Century timeline clicks into place: the 20 Allied Kingdoms, unable to defeat the Great Kingdom militarily, invaded the Lunarian “Land of the Gods” on the Red Line, seized Uranus, wiped the Great Kingdom from the map, and installed themselves in Mariejois — leaving the Lunarians nearly extinct and Uranus in Imu’s possession ever since.
6. Chapter 1090 (Volume 108): Saint Saturn explicitly lists the three things the World Government must protect on Egghead: Vegapunk’s brain (the Punk Records), the Mother Flame fusion reactor, and York. The Mother Flame is what powers the “Imu Cannon” — the weapon used to obliterate the Lulusia Kingdom. If the Lunarian tribe’s eternal flame is Uranus’s true power source, and the Mother Flame is an artificial recreation of that flame, then the World Government has spent 800 years trying to replicate the fuel they lost when they expelled the Lunarians. Zoro’s line in Chapter 1078 — “Their back flames just won’t go out!” about the Seraphim — confirms the eternal, inextinguishable nature of that Lunarian fire.

Our Analysis

The most compelling aspect of this theory is not any single piece of evidence — it’s the structural elegance of the “two plus one” framework. Oda has consistently organized his world in asymmetrical trinities: three Admirals but one Fleet Admiral, three Ancient Weapons but one Joy Boy to wield them correctly. The fact that Poseidon (Shirahoshi) is the only weapon native to the Blue Star, while Uranus and Pluton share the same destructive signature, strongly implies they are related in origin. A storyteller as meticulous as Oda does not give two weapons identical power profiles by accident.

The Void Century timeline proposed here also solves a problem that has nagged at fans for years: why would the 20 Allied Kingdoms need to erase all records of a kingdom they defeated? If they simply won a fair war, history would celebrate them. The erasure only makes sense if their victory was achieved through an act so morally catastrophic — stealing a god-race’s sacred weapon and using it to commit genocide against a beloved nation — that the truth would delegitimize their rule forever. The Lunarians didn’t just lose their home; they lost Uranus, their identity, and nearly their entire species. That is the secret the Poneglyphs are screaming.

The one significant counter-argument is the role of Momonosuke as Pluton itself versus Pluton being the physical warship beneath Wano. The manga has shown both: Momonosuke can command Zunesha (who can destroy Wano’s walls to reveal a warship), but some readings suggest Momo *is* the weapon in a metaphorical sense, as the “king” who activates it. This theory argues for the literal warship, and the manga’s Wano arc does seem to confirm a physical vessel. However, with Oda’s track record of subverting literal interpretations (Poseidon being a mermaid, not a ship), we should remain open to a final twist. What seems certain is that the endgame involves Pluton opening a passage through the Red Line — with Shirahoshi’s Sea Kings guiding Fish-Man Island’s inhabitants to safety in the aftermath — and that this act, not a conventional battle, is what “turns the world upside down.”

Theory Credibility Rating

The lunar mural evidence, the Seastone-Pyrobloin-Wano geological chain, the Binks’ Sake lyrical cipher, and Imu’s confirmed possession of a city-destroying weapon all provide strong multi-chapter support — but the theory earns four stars rather than five because Uranus’s exact form remains officially unconfirmed, and the “Pluton as Uranus rebuild” hypothesis, while structurally satisfying, still lacks a direct textual confirmation from the manga.

Source: https://hebochans.com/one-piece-ancient-weapon/