Nereus

Biodata

Feature	Value
Name	Nereus (涅柔斯)
Alias(es)	“Vampire”
Species/Race	Fish-Man; appears almost indistinguishable from a human
Gender	Male
Affiliation	Ryugu Kingdom; former associate of the Rocks Pirates
Occupation/Role	King of Fish-Man Island; founder and commander of the reorganized Neptune Army
Status	Alive
First Appearance	Chapter 1

Background / History

Nereus left Fish-Man Island after learning combat techniques and set out with several companions from the Fish-Man District. Witnessing the slave trade’s devastation of Fish-Man Island, he resolved to overthrow the World Government and end Celestial Dragon rule. His destruction of a World Government slave transport made him a wanted pirate, and his bounty later rose dramatically. 2

He established himself on Beehive Island, where his reputation deterred pirates from threatening his daughter Nanamo. He frequently clashed with Rocks D. Xebec, with one sparring match lasting seven days and seven nights; the two were considered capable of sinking Beehive Island if they fought seriously. Despite his proximity to the Rocks Pirates, Nereus did not share Rocks’s plans for a rapid victory over the World Government. 1 6

During the God Valley Incident, Nereus awakened his Devil Fruit, gathered blood from the island’s dead, rescued civilians, and worked with Kuma’s evacuation efforts. He later learned more about the circumstances surrounding Rocks’s death through the River of Death. 23 24 30 31

After God Valley, he returned to Fish-Man Island and began consolidating its scattered Fish-Man and merfolk population. He overthrew King Pontus, became king, expelled Neptune and the former royal loyalists peacefully, and publicly promised a safer nation. 74 76 77

As king, Nereus rebuilt the Neptune Army, expanded infrastructure, established training systems, regulated passage through Fish-Man Island, and pursued trade security. His actions sharply reduced kidnappings and trafficking around the island. 78 81 83 93 123

His conflict with the World Government escalated into a direct confrontation with the Five Elders. Unable to permanently kill one another, both sides reached a negotiated settlement granting Nereus rights over the Grand Line midpoint and a garrison presence on Sabaody Archipelago. 114 116 119

Appearance

Nereus is a towering Fish-Man whose outward appearance is close enough to human that his race is not obvious. In combat, his Vampire Fruit transformations make his predatory traits far more pronounced.

• Over three meters tall. 1
• Usually appears human, unlike Fish-Men with obvious piscine traits. 1
• Possesses broad, independent bat wings in hybrid form. 6 7
• Develops sharper nails, a more muscular build, and crimson-tinted pupils while transformed. 7 22
• Fights primarily with his hands rather than conventional weapons. 7

Personality

Nereus is strategic, disciplined, and focused on long-term change rather than indiscriminate piracy. His central objective is to dismantle the World Government and Celestial Dragons’ rule, particularly the systems enabling slavery and the exploitation of Fish-Men and merfolk. 2 6

He is protective toward his family, subordinates, and Fish-Man Island’s citizens. He personally safeguards Nanamo, trains younger allies, rescues civilians when possible, and makes the island’s security a priority. 1 16 48 77 83

His compassion is selective. Nereus can be ruthless toward slave traders, pirates, Cipher Pol agents, and Marines he considers threats, often using fear and public displays of force to protect Fish-Man Island’s interests. 43 51 89 109 144

Abilities & Skills

Vampire Devil Fruit

Nereus possesses a Vampire-themed Zoan Devil Fruit that grants flight, transformation, blood manipulation, regeneration, and the River of Death. His mastery lets him maintain a distinct hybrid form with independent wings. 6 7 249

• Can grow bat wings and fly freely. 6 7
• Manipulates blood from dead bodies within a range; living targets are not directly affected by this collection ability. 22 23
• Forms blood weapons, including spears, arrows, swords, and large-scale blood tides. 27 43 116
• Can drain blood from targets, including removing an enemy’s heart. 43 89
• His Devil Fruit awakening drew blood from corpses across God Valley into a massive blood sphere. 23
• Can transform others into lesser vampires; Ginny gained enhanced physique, self-healing, blood-draining, and bat-wing flight while retaining the ability to swim. 248 249
• His transformed vampires are subject to an implicit command influence from Nereus. 249

River of Death and Immortality

Nereus can dissolve into the River of Death and replace a destroyed body with another restored to peak condition, making ordinary lethal damage ineffective. 31 116

• Uses souls within the River of Death as resurrection resources. 346
• Can return after catastrophic wounds with his aura fully restored. 116
• Cannot be permanently killed unless an opponent breaks through his Haki defenses, destroys his heart while he is in his elemental-like state, and repeats the process countless times. 33
• His immortality allowed him to stalemate the Five Elders, who also possessed regenerative immortality. 116
• High-level souls such as Rocks and Roger retain diminished combat ability if forcibly controlled by the River of Death. 346

Haki

Nereus is an exceptionally advanced Haki user, capable of overwhelming high-level opponents and defending against attacks that would devastate his surroundings. 7 114

• Possesses Conqueror’s Haki comparable to Rocks’s, with highly concentrated infusion around his attacks. 7
• Uses Conqueror’s Haki to screen Neptune Army recruits for mental and physical strength. 82
• Maintains a Conqueror’s Haki barrier that Mars’s wind blades could not penetrate. 114
• Demonstrates powerful Armament Haki, including internal destruction applications. 99
• Can evade observation and remain undetected even by a CP9 chief with rudimentary Observation Haki. 43
• Can produce sword-like slashes even with an ordinary blade despite preferring unarmed combat. 82

Fish-Man Physiology and Water Combat

As a Fish-Man, Nereus possesses enhanced strength and underwater adaptability. Unlike conventional Devil Fruit users, he can continue fighting effectively in water. 1 20 21

• Produces a skin-tight, self-repairing bubble membrane that repels water and preserves his combat ability underwater. 21
• The membrane can be continuously replenished as long as he has stamina; its cost is compared to breathing. 21
• Can remain afloat after releasing his grip on the sea surface, despite being a Devil Fruit user. 20
• Can communicate with marine life, a rare ability even among Fish-Men. 30 44
• Persuaded a Sea King to tow his ship through the Calm Belt. 57

Combat Techniques

Nereus combines extreme speed, physical strength, Fish-Man techniques, Haki, and blood manipulation.

• Hell Stab — Condenses Conqueror’s Haki around his fingertips and launches himself like a spear. 7
• Secret Art: Blood Burst — Accelerates an opponent’s blood flow after contact, exploiting the vulnerability of internal organs. 99
• River of Death — A large-scale blood attack that can become a destructive blood tide. 31 116
• Can fight and defeat Logia users through Haki, as demonstrated against Ace. 346

Equipment / Weapons / Items

• Poneglyph weapons — Uses indestructible Poneglyphs as blunt weapons and sought methods to feed Devil Fruits to them. 81 82
• Red Snake and Black Tortoise — Poneglyphs transformed through Devil Fruit technology; deployed as battlefield weapons. 196
• Flail — Retrieved following his agreement with the Five Elders. 119
• Tamed sea beasts and Fighting Fish — Maintained for defense, transport, and military training. 4 17 82

Relationships

• Nanamo — Daughter; Nereus is deeply protective of her, trains her, and involves her in Fish-Man Island’s affairs. 1 16 82
• Charlotte Linlin — Ex-wife and Nanamo’s mother; their relationship began after Linlin met the powerful Fish-Man Nereus. 2
• Rocks D. Xebec — Former associate and repeated sparring partner; Nereus opposed Rocks’s broader plans despite their connection. 1 6
• Kaido — Former Rocks associate whom Nereus mentored and repeatedly fought; Kaido recognizes his strength and continues to seek a challenge. 47 231 330
• Sebastian — High-ranking subordinate and Neptune Army commander. 2 83 196
• Babel — Trusted subordinate and God Valley companion; Nereus is notably protective of him. 17 27
• Sunbell — Senior Fish-Man officer entrusted with administrative and military duties. 3 78
• Amphitrite — Lunarian ally rescued from CP9; Nereus treated her toxins, offered her shelter, and trained her in Haki. 43 44 48
• Fisher Tiger — Fish-Man District leader who wished to join Nereus’s crew; later co-led the First Legion. 51 83
• Kuma — Allied with Nereus during the God Valley evacuations and later facilitated his rapid travel. 24 26 95
• Zephyr — Marine adversary with whom Nereus has a tense relationship marked by threats, mutual recognition, and family-related incidents. 109 164 165
• Gol D. Roger — Former associate from the God Valley era; Roger entrusted Nereus with watching over Ace. 346
• Portgas D. Ace — Roger’s son; Nereus acts as an unwilling mentor and temporarily prevents him from entering the New World unprepared. 345 346

Story Role / Major Arcs

Beehive Island

Nereus is introduced as a feared Fish-Man leader on Beehive Island. He stops Kaido’s drunken destruction, protects Nanamo, manages his crew, and repeatedly clashes with Rocks. 1 2 6 7

God Valley Incident

He travels to God Valley with Babel, awakens his blood power, rescues civilians, confronts a Holy Knight, and becomes involved in the battle surrounding Rocks and Imu’s forces. 17 23 24 30 33

Rise of the Ryugu Kingdom

Nereus returns to Fish-Man Island, overthrows Pontus, becomes king, rebuilds the military, and turns the island into a more secure and organized state. 74 76 78 81

Conflict with the World Government

After repeatedly confronting Cipher Pol and Marine forces, Nereus battles the Five Elders at Mary Geoise. The resulting stalemate leads to a treaty recognizing major Fish-Man Island interests. 43 89 109 114 119

Deep-Sea Expansion and Sea Prohibition

Nereus uses Fish-Man Island’s strategic location to regulate trade and passage, confronts threats such as Vander Decken VIII and Harding, and makes the island’s power impossible for pirates and underworld groups to ignore. 93 144 148

Mentor to the Next Generation

He trains Nanamo, Amphitrite, Luffy, Alber, Chloe, and other younger figures, emphasizing Haki, practical combat, and the need to become strong enough to survive the New World. 48 83 190 215 346

Ace’s Arrival

When the Spade Pirates reach Fish-Man Island, Nereus reveals that Roger asked him to watch over Ace. He easily defeats Ace, teaches him the danger of the New World, and orders the Spade Pirates to remain on the island until they are better prepared. 345 346

Trivia

• Nereus’s bounty was once stated to be five billion Beli during the period when he was known as the “Vampire.” 181
• He can read ancient script and translate Poneglyphs. 44 95
• He knows the locations of all four Road Poneglyphs. 190
• Despite his fearsome reputation, he has no habitual preference for weapons and considers his hands his most familiar tools. 7
• His crew is composed largely of Fish-Men and merfolk because they find it easier to trust him as one of their own. 2