Poseidon

Poseidon
Statistics
Japanese Name:	ポセイドン
Romanized Name:	Poseidon
Official English Name:	Poseidon
First Appearance:	Chapter 612; Episode 531 (Shirahoshi)
Type:	Ancient Weapon

Poseidon is one of the three Ancient Weapons, alongside Pluton and Uranus. Poseidon is not an object but a living being: a mermaid endowed with the extraordinary ability to communicate with and command the Sea Kings. The power is currently manifested in Shirahoshi, the 16-year-old mermaid princess of the Ryugu Kingdom.

Appearance

Poseidon takes the form of a mermaid of the Ryugu Kingdom's royal bloodline. Upon her death, the ability she bore to commune with the Sea Kings was passed down to her descendants, who inherited her name as a title. Thus was born the lineage of the "Mermaid Princess" (人魚姫, Ningyo Hime^?). Currently, Shirahoshi has awakened this power and bears Poseidon's ability and name.

Abilities and Powers

The Sea Kings inadvertently summoned by Shirahoshi.

Poseidon possesses the power to commune with and command the Sea Kings, an ability beyond the reach of even the mightiest merfolk. This gift is regarded as one of the most formidable weapons in existence because of the Sea Kings' destructive potential to sink islands with ease. To command such beings is to hold dominion over a force that can either safeguard countless lives when guided by love, or plunge the world into ruin when driven by malice. To the Sea Kings themselves, the Mermaid Princess is revered as their queen.

When the current Mermaid Princess, Shirahoshi, first awakened her powers at the age of six, she lacked control over them, often summoning Sea Kings unintentionally through her loud cries—an innocent act that nonetheless could put her kingdom at risk. A decade later, in the midst of the battle against the New Fish-Man Pirates, Shirahoshi's ability fully awakened, and she at last appeared to have gained control of it.

History

Original Poseidon

The legendary Mermaid Princess Poseidon who could command Sea Kings.

Poseidon lived during the Void Century and formed a pact with Joy Boy. Under this agreement, she was to use her powers to command the Sea Kings to raise Noah to the surface and carry out its intended purpose: a mission whose details would only be revealed once it was completed. For reasons unknown, Joy Boy failed to honor his commitment to Poseidon.

Legacy

The Shandora Poneglyph, holding the secret to Poseidon.

After the Void Century, Poseidon vanished from the historical record. The only traces of her existence can be found on the Shandora Poneglyph in Skypiea and the Ryugu Poneglyph located in the Sea Forest, the latter taking the form of a letter from Joy Boy to Poseidon, in which he apologizes for breaking his end of their pact.

Even after Poseidon's passing, her power endured, transmitted through the generations of the Ryugu Kingdom's royal family, although it remained dormant. Meanwhile, Fish-Man Island sought to uphold its part of the bargain, despite Joy Boy's failure. For centuries, the World Government labored to prevent the awakening of the Ancient Weapons by forbidding the reading of the Poneglyphs.

Over time, Poseidon's story became legend within Fish-Man Island, with tales passed down through the Ryugu Kingdom royal family. One such legend foretold that a mermaid would be born with the power to control the Sea Kings, and that, on that day, a man would come to guide her. The first Vander Decken journeyed to Fish-Man Island in search of this mermaid, but failed. The story was then passed down through his descendants as well, with each new Vander Decken attempting in turn to find the princess.

Current Poseidon

Shirahoshi summons Sea Kings to stop Noah.

Eight years before the start of the series, Princess Shirahoshi had unwittingly demonstrated the ability to summon Sea Kings when her mother was under threat of being shot by the World Noble Mjosgard. Her cries called forth a group of the sea monsters, alerting both her mother and Vander Decken IX to her extraordinary ability. From this, Decken deduced that Shirahoshi was the legendary Mermaid Princess his family had long sought and resolved to marry her, to claim both her formidable abilities and her unparalleled beauty. Over the next ten years, he sent her persistent and threatening marriage proposals. Queen Otohime, fully aware that such powers could be both a blessing and a curse, ensured that her three sons—Fukaboshi, Ryuboshi, and Manboshi—trained rigorously to become capable warriors, prepared to protect Shirahoshi when the need arose.

Shirahoshi's power was finally fully awakened during the battle against the New Fish-Man Pirates, an event King Neptune himself noted with concern. Yet her mastery of the Sea Kings ultimately saved Fish-Man Island by preventing Noah from crushing it. Later, when Caribou overheard Nico Robin and King Neptune discussing the Ancient Weapons and Shirahoshi's role as Poseidon, he promptly attempted to abduct her to exploit her apocalyptic power. His scheme, however, was thwarted by the Straw Hat Pirates.

Trivia

• In Greek mythology, Poseidon (Ancient Greek: Ποσειδῶν, Poseidôn) is one of the Twelve Olympians and the god of the sea, water, storms, earthquakes, and horses. The name is consistent with the other two Ancient Weapons, which are also named after gods of ancient Greek religion. Additionally, it relates to the names of Shirahoshi's parents: Neptune is named after Poseidon's Roman counterpart, and Otohime is named after the daughter of the Japanese sea god, Ryūjin.
• Poseidon's power bears some resemblance to the ability to hear the Voice of All Things, which allows an individual to understand animals, including Sea Kings.
• The World Government nearly acquired Poseidon by coincidence during the Levely through Saint Charlos' short-sighted attempt to kidnap and enslave Shirahoshi, although Mjosgard ultimately prevented them from obtaining it.