Oak

Biodata

Feature	Information
Name	Oak (Tux Oak) 13
Alias(es)	“Terminator of the Battlefield” 1 13
Species/Race	Human; a transmigrator whose soul entered the body of a frail unborn child in West Blue 1
Gender	Male
Age	15 1 18
Affiliation	Rocks Pirates 10
Occupation/Role	Pirate apprentice 10 15
Status	Active 50
First Appearance	Chapter 1

Power Progression

Stage / Realm / Level	Chapter	Notes
Innate physical monster	1	Developed steel-like durability and Sea King-level strength in childhood; by ten, he could hunt Sea Kings and serve as a battlefield general.
Conqueror’s Haki awakened	2	Awakened during the crisis of his betrayal and CP0 capture; quickly learned to release it deliberately, knocking out ordinary personnel aboard his prison ship.
Armament Haki awakened	14	Comprehended Armament Haki through repeated combat with Haki users during his day-long battle against Kaido; immediately used it to shatter Kaido’s club.
Observation Haki awakened	29	Had recently awakened it, though his range remained too limited to search all of Sleeping Ancient Town alone; later used it against Kong’s attacks 29 50.
Bat-Bat Fruit, Mythical Zoan: Vampire Form	30	Gained hybrid and full-beast transformations, massive physical enhancement, crimson wings, and extreme flight speed.
Tri-Color Heart realization	32	Determined that his three-part heart may allow him to house and control three Devil Fruit powers without the usual fatal conflict.
Seven Star Sword acquired	34	Overpowered the sword’s corrupting will with Conqueror’s Haki and gained its destructive sword aura and Demon Fire.
Seven Star Sword fusion	35	Merged the sword into his body, allowing him to use its slashes and Demon Fire without holding the blade.

Background

Oak was reborn in West Blue after transmigrating into the body of an infant expected to die before birth. His body rapidly transformed from frail to monstrous, driven by an enormous appetite and abnormal physical development 1.

At five, Oak returned from a hunt to find his village—including his parents—slaughtered by wolves. He killed the entire pack alone. By age ten, he was capable of hunting Sea Kings and was recruited as a general during the wars among five island kingdoms. He spent the next five years ending battles from the front line, surviving countless engagements without injury and earning the name “Terminator of the Battlefield” 1 13.

His kingdom’s king secretly sold him to the World Government in exchange for membership. Oak survived a Sea King-strength anesthetic, destroyed the royal palace, routed the kingdom’s army, and fought to the port. The drug reduced him to less than a tenth of his strength, allowing five CP0 agents to capture him only after exhausting him in battle 1.

CP0 kept Oak sedated aboard a prison transport because conventional restraints and injections could not reliably contain him. His captivity and betrayal awakened his Conqueror’s Haki before Golden Lion Shiki destroyed the transport and brought him to Hachinosu for a meeting with Rocks D. Xebec 2 3.

Appearance

Oak is a two-meter-tall, lean young man with short blue hair, fair skin, refined features, and a muscular build that conceals his abnormal physical strength 4 16.

• His ordinary appearance is notably handsome enough to attract attention within the Rocks Pirates 16.
• In Vampire hybrid form, his hair and eyes turn scarlet, his skin becomes corpse-pale, and crimson wings emerge from his back 30.
• In full Vampire Beast Form, he grows to nearly Kaido’s size and develops pronounced fangs 30.
• After merging with the Seven Star Sword, he bears a green sword-shaped mark on his chest 35.

Personality

Oak is fiercely independent and reacts violently to betrayal or attempts to control him. His capture by his own kingdom left him resentful of being deceived, while his decision to join Rocks came from a desire to grow among stronger opponents rather than fear of Rocks’s power 1 4 10.

He is ambitious, competitive, and openly provocative. Oak taunts Kaido relentlessly, refuses to accept Shiki’s superiority as permanent, and wants to become strong enough to surpass Rocks himself 4 14 32. He also possesses a pragmatic, calculating side: he hides the source of his foreknowledge, monitors Ochoku without making an unproven accusation, and actively seeks to alter Rocks’s future downfall 19 26 46.

Oak is socially bold and often shameless. He relies on flattery to defuse conflicts, repeatedly charges expenses to Kaido, and frequently makes crude, unwanted flirtatious remarks toward women such as Tsuru and Shakuyaku 16 37 49.

Abilities & Skills

Monstrous Physiology

Oak’s body possesses extreme natural strength, durability, stamina, and recovery even without Haki or Devil Fruit transformations.

• Withstood artillery, blades, bullets, and Kaido’s Haki-coated club with little or no injury 1 12 13.
• Destroyed large warships with single punches 7 8.
• Fought Kaido continuously for a full day and night before defeating him 14 15.
• Endured Kong’s bone-shattering internal-force punches and continued fighting 50.
• His physical resilience has been compared to Charlotte Linlin’s “Steel Bone Balloon” 3 12.

Combat Mimicry

Oak has exceptional perception and learns combat techniques by observing or experiencing them.

• Learned Hasshoken from mercenaries of the Happo Navy and Soru during his fight with CP0 3 4.
• Awakened Armament Haki without formal instruction after repeated exposure to Haki users 14.
• Still struggled to comprehend Conqueror’s Haki Infusion despite mastering simpler techniques quickly 21.

Haki

Oak possesses all three forms of Haki.

• Conqueror’s Haki — Awakened under extreme pressure; can release it at will to incapacitate weaker opponents and suppress the Seven Star Sword’s murderous influence 2 34.
• Armament Haki — First manifested against Kaido, reinforcing his strikes strongly enough to break Kaido’s weapon 14.
• Observation Haki — Recently awakened during the Punk Hazard expedition; used to anticipate Kong’s movements in battle 29 50.
• Limitation: Oak has not yet mastered Conqueror’s Haki Infusion and was told that direct experience of the technique’s backlash is necessary to learn it 21 22.

Vampire Fruit

Oak ate the Bat-Bat Fruit, Mythical Zoan: Vampire Form, a Mythical Zoan associated with vampire transformations 30.

• Gains hybrid and full-beast forms that substantially increase his strength, speed, and physique 30.
• Can fly at near-teleportation speed, though he cannot maintain that speed while carrying another person 31 48.
• Can pierce even Kaido’s durable body with his fangs through the fruit’s rule-like effect 31.
• Drains blood and lifespan from victims, weakening them while extending his own vitality and preserving his youth 31.
• Can heal severe injuries by absorbing blood and replenishing life force 32.
• Uses bat-like senses and ultrasonic waves to locate targets and detect hidden activity 43 45.
• As a Devil Fruit user, he can no longer swim 45.

Tri-Color Heart

Oak possesses one unusually large heart divided into three distinct, differently colored sections 30.

• The Vampire Fruit’s power settled into only one section rather than spreading through his body 32.
• Oak believes this structure may let him safely contain three Devil Fruit powers, though this remains his conclusion rather than a confirmed achievement 32.
• The fused Seven Star Sword’s power also flows into one of his heart sections 35.

Seven Star Sword

The Seven Star Sword is an ancient cursed weapon that absorbed the hatred and bloodshed of Asuka Island’s civil war 34.

• Oak resisted its attempt to flood his mind with murderous impulses by overpowering it with Conqueror’s Haki 34.
• Its sword aura can split a mountain peak even with Oak’s limited conventional swordsmanship 34.
• The blade produces green Demon Fire, a heatless force that functions as shockwaves, extended slashes, and destructive fireballs 35.
• Oak can merge the sword into his body and produce its attacks from any part of himself without physically wielding it 35.
• The weapon’s true nature is unknown; Oak speculates that it may be Devil Fruit-related or an embodiment of Asuka Island’s wishes 35.

Martial Arts and Mobility

• Hasshoken: Extreme Impact — A self-modified internal shockwave technique that transmits force through targets or weapons, damaging them from within 12.
• Fist Bone — A Garp-inspired heavy punch technique used against Kaido 13.
• Soru — High-speed movement technique learned from CP0 3 4.
• Geppo — Air-stepping technique used for aerial movement before obtaining the Vampire Fruit 29.

Equipment / Weapons / Items

• Seven Star Sword — Ancient cursed sword fused into Oak’s body; grants sword aura and Demon Fire abilities 34 35.
• Sea chart of Sleeping Ancient Town — Used to lead Rocks, Newgate, and Kaido to the hidden Vampire Fruit 29.

Relationships

• Rocks D. Xebec — Captain and primary benefactor. Rocks recruited Oak after recognizing his ambition; Oak later becomes committed to changing Rocks’s fate while aiding his plans 10 19 26.
• Kaido — Fellow apprentice, constant rival, and frequent victim of Oak’s taunts and unpaid bills. Oak defeated him to establish superiority, though they later cooperate in battle 10 15 17 46.
• Edward Newgate — Senior crewmate and informal mentor. Newgate welcomes Oak into the crew, drinks with him, and agrees to teach him the path toward Conqueror’s Haki Infusion 15 21 22.
• Golden Lion Shiki — Rescued Oak from CP0 and delivered him to Rocks. Oak resents Shiki’s earlier defeat of him and vows to surpass him 3 4.
• Charlotte Linlin — Mutual flirtation and physical affection develop after Oak joins the crew; Linlin reacts jealously to his attention toward Gloriosa 10 39.
• Tsuru — Marine adversary. Oak repeatedly provokes her, while Tsuru considers him a dangerous future threat and tries to capture or disable him 6 8 49 50.
• Steel Bone Kong — Navy Admiral whom Oak confronts while delaying the fleeing Marine fleet. Oak can match his raw strength briefly but is outclassed by Kong’s experience and refined Haki 49 50.
• Ochoku — Crewmate whom Oak privately suspects will betray the Rocks Pirates. Oak watches him closely but refuses to accuse him without proof 19 26 46.

Story Role / Major Arcs

• West Blue and CP0 captivity — Oak rises from orphaned child to undefeated battlefield general, then is betrayed by his king and captured by CP0 while drugged 1 2.
• Rescue and Marine encounter — Shiki frees Oak from the prison transport, defeats him, and brings him toward Hachinosu; Oak subsequently clashes with Sengoku and Tsuru during Shiki’s escape 3 6 8.
• Rocks Pirates recruitment — Oak accepts Rocks’s invitation after hearing his goal of ruling the world and immediately begins a rivalry with Kaido 10 11.
• Battle for apprentice supremacy — Oak and Kaido devastate Hachinosu in a day-long duel. Oak awakens Armament Haki, defeats Kaido, and seeks promotion beyond apprentice status 12 15.
• Rocks’s ambitions and foreknowledge — Oak supplies Rocks with knowledge concerning the Dark-Dark Fruit, Nidhogg, Pluton, and the Great Hammer Warband while concealing his true source of information 17 18 27 28.
• Changing fate — Oak decides to prevent the future collapse of the Rocks Pirates, identifies Ochoku as a likely traitor, and convinces Rocks to investigate Punk Hazard with a restricted group 19 26.
• Ancient relic expedition — After Punk Hazard yields no frozen giants, Oak leads Rocks, Newgate, and Kaido to Sleeping Ancient Town, where he acquires the Vampire Fruit; he later claims and fuses with the Seven Star Sword on Asuka Island 29 30 34 35.
• Putekoloni raid — Oak identifies the monastery’s weak defenses as suspicious, survives its trap, and uses his Vampire Fruit to hunt and drain escaping guards after the crew discovers its mass atrocities 43.
• Marine encirclement — Oak helps fight a fleet of more than one hundred Marine warships, defeats the giant warrior “Opening Bro,” and pursues the retreating fleet alone 46 47 48.
• Battle against Kong — Oak delays Admiral Kong and Tsuru by teleporting among warships, destroying vessels with the Seven Star Sword while relying on his durability to survive Kong’s attacks 49 50.