What If Blackbeard Learns Shirahoshi Is Poseidon?

Why Poseidon May Be the Easier Target

If Blackbeard learns where both weapons are, Poseidon may be the more reachable target. Pluton lies beneath Wano, and getting to it would mean overcoming the country’s formidable geography before dealing with its defenders. Knowing where the warship rests gives Teach an objective, but no obvious way to claim it.

Poseidon is Princess Shirahoshi. Her ability to communicate with the Sea Kings makes her one of the most important people in the world, and the Fish-Man Island arc showed what those creatures can do when they answer her call. Shirahoshi’s power is extraordinary, even though she has not learned to control it fully.

That lack of control might not discourage Teach. The Blackbeard Pirates abducted Charlotte Pudding, whose Three-Eye Tribe heritage gives her the potential to decipher Poneglyphs if her ability awakens. Teach’s crew has already shown an interest in what someone may become capable of doing, rather than waiting for that power to develop.

Fish-Man Island Needs More Than Hope

The possibility of an attack on Fish-Man Island is frightening because Blackbeard would not have to conquer or destroy it to achieve his immediate goal. If his crew came for Shirahoshi, an abduction could be enough. The island has defenders, but facing an Emperor and his Titanic Captains would be a severe test for them.

Taking Shirahoshi would not automatically give Teach command of the Sea Kings. Her power belongs to her, and the story has not established that Blackbeard could force her to use it. Capturing her would still be catastrophic: Fish-Man Island would lose its princess, and a pirate with a record of exploiting valuable captives would hold Poseidon.

Blackbeard is already dangerous without an Ancient Weapon. He possesses the darkness power of the Yami Yami no Mi and the devastating quake power once wielded by Whitebeard. Adding Shirahoshi to his plans would give an already formidable crew a new way to threaten the balance of power, even if Teach could never control her ability himself.

Devon’s Saturn Disguise Adds Another Possibility

Catarina Devon’s encounter with Saint Jaygarcia Saturn on Egghead gives this theory another unsettling piece. After touching him, Devon gained the ability to copy his appearance. That could help the Blackbeard Pirates deceive someone who recognises Saturn, though his face alone would not guarantee them access to World Government secrets or restricted locations.

Van Augur’s teleportation power makes the crew harder to contain, while Caribou may be able to supply information about Poseidon and Pluton. Put those advantages together and Teach has several possible ways to exploit a moment of confusion. None confirms a plan to attack Fish-Man Island, but each fits his habit of collecting opportunities before making a move.

The timing remains unknown. Caribou asked to be brought to Blackbeard; the story has not shown Teach using the Ancient Weapon secrets. Until that happens, an operation involving Devon’s disguise, Van Augur’s powers, and Shirahoshi is a theory built from pieces already on the board.

Why Shanks and Luffy Could Be Drawn In

Shanks has taken Blackbeard seriously for years, and their history gives any future encounter considerable weight. A clash may feel inevitable, but One Piece has not promised when or how it will happen.

For Luffy, the stakes are already personal. Teach captured Ace and handed him over to the Marines, helping set in motion the events that led to Ace’s death. Luffy also has a bond with Shirahoshi and Fish-Man Island. If Blackbeard threatened her, Luffy would have every reason to get involved.

There is a larger difference between the two pirates. Luffy speaks of becoming Pirate King as a path to freedom. Blackbeard pursues power through calculation, theft, and the ambitions of the people he gathers around him. What Teach ultimately wants for the world remains unclear, but a move against Poseidon would bring those opposing approaches into direct conflict.

The prophecy that Luffy will destroy Fish-Man Island adds another question. A Blackbeard attack could play a part in the island’s future, but there is no evidence yet that he causes the foretold destruction. Treating the prophecy as a warning is fair; assigning Teach a confirmed role in fulfilling it would be getting ahead of the story.

The Real Danger Is Timing

The greatest opportunity for Blackbeard may be a divided world. The World Government faces mounting pressure, the Revolutionaries are making their moves, and several pirate crews are competing for the One Piece. Teach has always been good at acting while stronger opponents are occupied elsewhere.

Caribou’s knowledge could make that instinct more dangerous than ever. If he tells Teach what he knows, the Blackbeard Pirates may learn that Shirahoshi is Poseidon and that Pluton lies beneath Wano. Information alone cannot win either weapon, but it can tell a patient pirate where to look.

Fish-Man Island is therefore a plausible target, not a confirmed destination. Blackbeard might pursue Shirahoshi, seek Pluton, or choose a move nobody has anticipated. The worrying part is that he may soon have enough information to make that choice.

— ForgottenBlade_Ace
Primal Misfit Overlord | The Glitch ;⁠-⁠)

For more context from One Piece’s current arc, with spoilers, see our Elbaf arc recap.