Grey

Biodata

Feature	Information
Name	Grey
Alias(es)	Dr. Thomas Grey 48 49
Gender	Male 4
Affiliation	Rod Pirates; Twelfth Division Captain 14 269
Occupation/Role	Scientist, ship designer, materials researcher, and weapons engineer 4 227
Bounty	47,000,000 Belly 73
First Appearance	4

Power Progression

Stage / Realm / Level	Chapter	Notes
Shipbuilding specialist	4 14	Pursued funding for his warship research through the Felke Family, then designed the crew's cannon-equipped ship, the Polar.
Gulp-Gulp Fruit user	130 142	Consumed a Devil Fruit and gained the ability to eat, fuse, and improve materials.
Devil Fruit mastery	139	Developed combat methods suited to his abilities during the crew's training on Drum Island.
Deep Blue No. 1	142	Fused a self-developed energy device into his body; it can produce enough power to run a large Marine warship.
Hades battle armor	142	Created Thomas No. 1, a memory alloy that forms ultra-thin armor over his body when powered by Deep Blue No. 1.
Giant robot transformation	144 150	Uses the Gulp-Gulp Fruit to form a giant robot body, allowing him to apply his overwhelming strength with greater precision.

Background

Grey was a financially struggling scientist on Minion Island whose overriding ambition was to build an exceptionally powerful warship. He accepted the Felke Family's offer to design weapons because it promised funding and practical opportunities for his shipbuilding research. He was particularly interested in the Marines' technology for navigating the Calm Belt and dreamed of surpassing the legendary warship known as Hades. 4

The Felke Family's offer was a trap: Fulk Kyle intended to confine Grey as a weapons designer and murder Rod, Nia, and Nerl to keep the arrangement secret. Grey rejected the coercion despite Kyle's threats, only to be caught in the destruction of the manor during the ensuing battle. He survived with four broken bones and lamented that he had never completed even an ordinary boat. 6 8

After recovering, Grey became the Rod Pirates' ship designer. He built the Polar as their home at sea and chose to sail with the crew, despite repeatedly questioning the wisdom of fighting powerful organizations such as the Donquixote Family. 14 15

Appearance

Grey initially resembles an exhausted, disheveled researcher. After developing his Devil Fruit, he extensively modifies his body and can manifest the sleek Hades battle armor. 4 142

• Long, messy hair and an untrimmed beard. 4
• Stained white work coat and tattered bucket hat. 4
• Prominent dark circles beneath his eyes. 4
• A pale-blue circular energy ring embedded in his chest after modifying his body. 142
• Metallic skin and form-fitting armor created from Thomas No. 1 when Hades is activated. 142

Personality

Grey is an eccentric, talkative scientist whose enthusiasm for technology often becomes an uncontrollable monologue. He is intensely proud of his ideas, readily calls himself a genius, and can become absorbed in machinery, weapon blueprints, unusual materials, and scientific phenomena even in dangerous situations. 4 49 78

Early in his journey, Grey is openly fearful of combat. He pretends to be defeated during the battle at Spiders Mill, calls himself unable to lift a chicken, and tries to avoid confrontations whenever possible. His interest in valuable technology and weapon stockpiles can rapidly overcome that fear. 15 19

After obtaining the Gulp-Gulp Fruit and modifying himself, Grey becomes far more confident and even excited by battle. However, he remains a poor conventional fighter: his stance is unrefined, he struggles to judge appropriate force, and his raw power makes fighting beside him hazardous. 142 144

Abilities & Skills

Scientific Expertise

Grey specializes in materials science and mechanics. He can quickly understand unfamiliar advanced technology, synthesize new materials, improve machines, and develop weapons or vehicles for specific users. 49 227

• Designed the Polar and later modified it with wings for the voyage to Sky Island. 14 169
• Created an automatic cooking machine for the crew. 28
• Understood the Marine warship's turbine-based power system after examining its blueprint. 49
• Improved a Marine warship's transmission equipment beyond its original performance, then sabotaged its engines to disable pursuing vessels. 52 55
• Studied Enel's Ark Maxim blueprints and worked with Water Seven shipwrights, including Franky, on heavy-artillery warship designs. 174 192
• Developed new materials and technologies that improved production across the Rod Pirates' territories. 221 227

Gulp-Gulp Fruit

Grey can consume objects and integrate, fuse, or improve their properties. He uses the fruit primarily for self-modification, materials development, and mechanical transformation. 142

• Can eat metals and use them to reinforce his body. 142
• Improved his physical condition to roughly match Nia's condition when she first set sail. 142
• Can transform into a giant robot form. 144 150
• His extensive modifications allow him to endure the recoil from his own immense power. 142
• He was initially vulnerable to Perona's Negative Ghosts, which passed through his physical defenses and left him in despair. 142

Deep Blue No. 1

Deep Blue No. 1 is Grey's internal energy device, fused into his chest through the Gulp-Gulp Fruit. It generates extreme power from a compact structure. 142

• Can provide enough energy to power a small sailboat for three days from a fist-sized device. 142
• Grey's integrated version can power even the largest Marine warships. 142
• Lets his punches unleash force sufficient to destroy zombies and shake a Marine warship. 142

Hades Battle Armor

Hades is Grey's ultra-thin armor system, formed from the memory alloy Thomas No. 1 and powered by Deep Blue No. 1. 142

• Provides steel-like durability and protects Grey from the recoil of his own attacks. 142
• Can deploy hidden firearm systems and air jets for aerial mobility. 204 205
• Allows him to fire Haki-infused bullets capable of neutralizing Baby-5's cannon fire. 205
• Its armor-mounted weapons were used alongside his allies to help overwhelm Vice Admiral Vergo. 210
• Grey lacks fine control over its output and can cause major structural damage with ordinary punches. 144

Equipment / Weapons / Items

• Polar — The Rod Pirates' ship, designed by Grey and later repeatedly upgraded. 14 169 192
• Deep Blue No. 1 — Internalized high-output energy device. 142
• Hades — Thomas No. 1 memory-alloy battle armor. 142
• Custom weapon systems — Guns, artillery, rockets, propulsion equipment, and user-specific weapons designed for the crew. 90 205
• Ark Maxim blueprints — Enel's propulsion designs, which Grey studied after the Sky Island campaign. 174

Relationships

• Rod — Captain and the person who brought Grey into the crew. Rod values Grey's technical ability but regularly cuts off his long-winded explanations. 8 14 90
• Nia — Crewmate and frequent critic of Grey's cowardice, rambling, and reckless combat output; she also suspected him of being a Marine spy during the Tiger Shark Island incident. 19 55 144
• Nerl — Fellow North Blue crewmate who certified Grey's scientific ability, accompanied him in searching the Donquixote treasury, and works with him on technical projects. 8 19 28
• Trafalgar Law — Crewmate who treated Grey's injuries after the Felke Family battle and later helped manage his Devil Fruit acquisition. 11 130
• Franky — Water Seven shipwright who collaborated with Grey on warship design work and was later his vice-captain in the Twelfth Division. 192 269
• Lilika — Partnered with Grey to capture Buffalo and Mahalbas during the Dressrosa conflict. 209
• Gilbert Garon and Luca — Marine officers Grey deceived as “Dr. Thomas” to gain access to advanced Marine warship technology. 48 49

Story Role / Major Arcs

Felke Family Incident

Grey's attempted partnership with the Felke Family led Rod, Nia, and Nerl to Minion Island. Kyle's betrayal forced Grey to choose between becoming a captive weapons designer or defying the gangsters; he chose his companions and survived the destruction of Island Manor. 4 6 8

Joining the Rod Pirates

Grey designed the Polar and joined the crew when it departed Flying Swallow Island. He contributed ship improvements, cooking machinery, weapons research, and storage modifications while the crew entered the Grand Line. 14 28 30

Tiger Shark Island Infiltration

Seeking special materials and Marine technology, Grey entered the Marines' warship under the persona of Dr. Thomas Grey. He impressed the ship's repair specialist with his understanding of its power system, modified its transmission equipment, and secretly sabotaged multiple pursuing warships to aid the Polar's escape. 48 49 52 55

Devil Fruit Development and Thriller Bark

After consuming the Gulp-Gulp Fruit on Drum Island, Grey trained in secret and developed a self-modified combat body. On Thriller Bark, he unveiled Deep Blue No. 1 and Hades against Moria's zombies, later using a giant robot transformation to control his destructive power more effectively. 130 139 142 144

Ship Upgrades and New World Expansion

Grey modified the Polar for its ascent to Sky Island, researched Ark Maxim's technology, and collaborated with Water Seven shipwrights on a new heavy-artillery warship. He later became a key technical figure in the Rod Pirates' expansion, developing new materials and helping build Silver City as Twelfth Division Captain. 169 174 192 221 269

Dressrosa Conflict

During the war against the Donquixote Family, Grey criticized Baby-5's limited use of the Arms-Arms Fruit, attempted to recruit her, and used Hades' integrated weapons against her. He later worked with Lilika to capture Buffalo and Mahalbas. 204 205 209

Notable Quotes

“The weak scientist of the past is gone. I'm very strong now!” 142

“If I can build battle armor, I can build warships!” 142

Trivia

• Grey's lifelong ambition is to build a warship powerful enough to surpass the legendary ancient weapon Hades. 4
• He named his battle armor Hades because he wants it to become a legend comparable to an ancient warship. 142
• Despite initially fearing battle, Grey later calls himself the “real MVP” after his engine sabotage decisively cripples the Marine pursuit. 55