Kuro is a pirate who disguised himself as Butler Beauregard ( Klahadore in the original) to enjoy a life of wealth and tranquility. He is also called the mastermind.
Contents
Appearance
Kuro is a tall, slender man. He has combed back black hair and wears round glasses. He always pays attention to a good style of dress. As a pirate captain, he always wears a long black coat over his normal clothes, with the mark of his gang on his shoulders. As a butler, and also when fighting the Straw Hat Pirates, he wore a classy black suit with a tie over a white shirt. The marks on his jacket bear some resemblance to dog turds. He also wears very strange grey and black striped shoes. In his pirate days he also always wore his fur gloves with claws, but later only in battle.
Personality
Black is a pirate who is tired of the pirate life and tired of being constantly pursued by the navy. So he longs for peace and a life of luxury. To this end, he is a very ruthless and sadistic person, though he is also extremely adept at playing the nicest person, thus fooling other people, in this case quite Syrop. He is so ruthless that he kills his own men just to carry out his plan. He also never once shows remorse for his actions.
What’s interesting about this is that he’s supposed to be one of the most intelligent people in One Piece, which Oda mentions himself in volume 8, so he has the highest IQ to that point after Benn Beckman. Up until his run-in with the Straw Hat Pirates, none of the captain’s plans ever failed, earning him the nickname “the mastermind”. He got into the habit of always pushing his glasses up with the heel of his hand to avoid hurting himself with his claws. He kept this habit even when he was Butler Beauregard. Jango noticed this, and thereby discovered that Kuro had lost none of his old strength in the three years he had not fought. The Nyaban Brothers had overlooked this detail.
Skills and strength

Black’s strength is his speed combined with his claw fighting technique. He runs 100 meters in just four seconds. That’s so fast, he’s undetectable to the naked eye. Kuro is feared by his own crew because his attacks are so fast and barely visible. To do this, he uses a strange stepping technique and his clawed gloves. His technique can be compared to shaving in terms of speed. The claws on his fingers are the length and shape of katana blades. His strongest attack is the death hump.
Past
The end of Kuro

Kuro used to be captain of the Black Cat pirate gang until he came up with a plan to retire. He and Jango managed to trick the Navy: he killed the entire crew of a Navy ship, except for the captain, Morgan, whom he still broke the jaw. Jango then hypnotized a member of his own gang, Nugire Yainu, and tricked him into thinking he was Kuro. Captain Morgan was also hypnotized into thinking Nugire Yainu was Kuro. Nugire Yainu was executed by the Navy, and Kuro was thus declared dead.
Living in Syrop under the name Beauregard

Kuro then took the pseudonym Beauregard. Three years before the Straw Hat Pirates arrived, he arrived at Miss Kaya’s mansion in Syrop, nearly starved. Kaya’s father took him in and had him cared for. He worked as a butler on the estate ever since. Two years after that, Kaya’s father passed away and since then Beauregard has been looking after Miss Kaya’s well-being. Black gained Miss Kaya’s trust and became her friend. He was always there for the girl and also became Kaya’s closest confidant. He also gained the trust of the villagers, who took the friendly butler to their hearts. Only Usopp distrusted Beauregard.
Present
The plan

Three years later, he tried to put his plan into action: He was going to kill Miss Kaya and have his gang attack the village. But before that, Miss Kaya was to sign a will that included Beauregard as sole heir. No one in the village would think it strange that she bequeath everything to him, for he had been loyal to her for three years. However, if she did not sign the will willingly, Jango would hypnotize her before Black then tried to kill her. Black hid from his gang that they were all to die as well, for he would never let them get as far as the village, as he wanted to live there in the future.
The fight

But exactly one day before the plan was to be carried out, Luffy, Zoro and Nami ran into the island. They befriended Usopp there. Later, Luffy and Usopp overheard Black talking to Jango on the beach about carrying out the plan. The Straw Hats and Usopp then prepared to defend the village at a narrow ravine facing the village. The attack by the Black Cat pirates was to be imminent the next morning, however the pirates did not come. Usopp remembered that there was another ravine up the beach to the village, on the other side of the island. The four of them immediately set out. Stopped by various events, a fight with the pirates ensued. Zoro had to stand up to Buchi and Siam, who later abandoned the fight and attacked Black, who was very angry about the tardiness of his crew and called them failures. However, they were without a chance.

Black gave the team one last chance to eliminate the Straw Hats within a time limit. Zoro, however, managed to defeat the Nyaban Brothers, even after Buchi gained tremendous strength from Jango’s hypnosis. Jango took over the pursuit of Miss Kaya, who was taken into the forest by Usopp’s band of pirates. Zoro and Usopp rushed to assist, while Luffy took over the fight against Black. Black gave the straw hat a hard time with his high speed. However, after Luffy was able to counterattack, Black began to use the Death Hump and decimate his own team. Luffy, unable to bear this, managed to catch Black and defeated him with the Gomu Gomu no Kane. Kaya was rescued and the Black Cat pirates departed with their unconscious captain.

Another pirate
This information comes from an anime filler.
As a result, Black was back with his gang as a pirate on the East Blue. He was seen looking at Luffy’s first wanted poster.
Miscellaneous
- Kuro was briefly called Captain Po by his gang because he told them he didn’t want to hear his real name anymore.
- Kuro bears astonishing similarities to Killer Kevin from Frank Miller’s comic Sin City. Both fight with long claws (in Kevin’s case his fingernails) in an extremely fast and silent manner. They also have similar hairstyles and clothing styles, as well as round glasses, which they often have to adjust. Add to that the ruthless and sadistic nature. Since Miller’s comic was published in 1991, before One Piece, it can be assumed that Oda was inspired.
- Kuro’s favorite food is bananas.