Personality:During the time he was in Water 7 as a carpenter, Rob Lucci never spoke, preferring to instead talk through his pet pigeon, Hattori, using ventriloquism. However, after he revealed himself to be a CP9 agent he spoke normally, with Hattori becoming a regular pigeon that displayed some human qualities. Hattori always rides on Lucci's shoulder until Lucci begins fighting, at which point he will fly overhead until the battle is over. Lucci seems to have a rivalry with Paulie, and often chides him for having money problems. Because of this rivalry, the two often fight; however, the matches generally end before there is a victor. Other than this, however, Lucci appears to be very distant from everyone else, including the other foremen and Iceburg.
Lucci comes off as a cold and collected CP9 agent, almost never displaying any emotions (nevertheless even he displayed shock at the knowledge that Franky had the Pluton blueprints the whole time, and is shown smirking when convincing Kaku and Kalifa to eat Devil Fruits as well as when he and Spandam realized Luffy was following them, probably because of his lust for battle). In spite of his seeming lack of emotions, he does not like being insulted. During his fight with Luffy he did not pay attention to Usopp, until he started to insult him. An example is the brutal assault on his friend of five years, Paulie, whom he even tried to kill after the CP9's identities had been revealed. He also states that he feels no true bond with the city he's lived in for five years, and he seems to have no feelings for his fellow CP9 colleagues, least of all Spandam.
Interestingly enough, he does react rather violently if anyone calls him a gakki (slang in Japanese for kid or brat), responding with a kick and a retort both times after Iceburg and Franky referred to him as such. He finds it offensive when someone speaks weakness around him, and going as far as to dismiss a new colleague by presumably killing him for being weak. The reason that he killed the five hundred soldiers in his past was due to another belief of his - the belief that weakness is a sin. He also believes if he is involved then the situation means blood will be drawn and that he also does not have to accept the views and ideals of his superiors as long as he completes his missions efficiently.
In combat, he is a very violent fighter, and seems to derive amusement and gratification from inflicting physical and emotional pain on others, making him a typical sadist. These scenes, along with when he anticipates battle, are the only times where he seems happy at all. In the Tower of Justice at Enies Lobby, he reveals that he only joined the World Government so he can be legally allowed to kill people. An example of Lucci's lust for violence is when he compromised the mission of bringing Robin to the Gates of Justice by allowing Monkey D. Luffy to tail him, for the sole purpose of having a battle, smirking when Luffy burst through the door. Lucci's violent and cruel nature is also shown when he goes into full-beast mode during battle, in order to attack Luffy more violently. Another example of his sadism is when Lucci flooded the underwater passageway to the Gates of Justice in an attempt to kill the Straw Hat crew members in the passageway, because he wanted to eliminate Luffy's chances of having everything just to anger him.
Despite all this apparent lack of morality, he has displayed some, if very little, sympathy for those he dubs innocent; when the Candy Pirates are attacking a small village, he quickly dispatches the captain to save the people, though his demonstration of Absolute Justice later prompts him and his comrades to leave. This shows that deep down, he's not completely heartless.
History:Twenty-two years before the start of the series, a six-years old Rob Lucci (alongside an eight-years old Blueno and a thirteen-years old Jabra) was seen training to master the Rokushiki style and in assassination with the other CP9 hopefuls on their homeland when Gol D. Roger was executed.
Notably, Hattori (or possibly another pigeon that serves as a predecessor to Hattori) was around back then — he was perched on top of Lucci's hat; Lucci has already sported his top hat, even in training. They trained hard in order to be "stronger than justice". In the anime, Kumadori and Fukuro were also seen training with them
Lucci's back-story concerning his admission into CP9 is revealed by Vice Admiral Doberman during the Buster Call on Enies Lobby. According to Doberman, fifteen years prior the start of the series, a kingdom had five hundred of its soldiers taken hostage by a pirate crew, with the captain demanding to be made the new king of the kingdom. As the government saw the king beginning to admit defeat, they sent in the thirteen year-old Rob Lucci.
He infiltrated the prisoners' holding ground, killed all five hundred hostages in the room, thus neutralizing the possibility of a trade and eliminating the soldiers that Lucci believes to be weak, and then mercilessly took the captain's head, as well as killing the rest of the pirate crew. During his confrontation, the crew fired upon him with firearms which left him with the noticeable scars across his back; the fact that he survived these shots was the first indication to the World Government of how strong Rob Lucci would turn out to be.
Strengths:Lucci has complete mastery of Rokushiki, having used at least one or more moves from each of the different forms, such as Rankyaku Hyoubi and Tobu Shigan: Bachi. He demonstrates this when he unveils the Rokushiki hidden technique, Rokuougan, during his fight with Luffy. The massively powerful technique is so strong that it causes severe internal injury to Luffy's body, who described its effect as an Impact Dial with greatly amplified power; no small feat considering that he is made of rubber. With his complete mastery of Rokushiki, in conjunction with his Devil Fruit ability, Lucci proved to be a resilient and formidable foe, fighting on an equal footing with Luffy in Gear Second, and literally forcing him to exert every ounce of strength against him.
Rob Lucci ate the Neko Neko no Mi, Model: Leopard, a Zoan-class Devil Fruit which allows him to transform into a leopard and a giant leopard-human hybrid. As Zoan class Devil Fruits enhances physical capabilities the most, it is most favored by martial artists like Lucci. Also, being a carnivorous animal, Lucci is more bloodthirsty and predatory than a regular Zoan class user, proven when he mauled Luffy as an actual leopard.
It has been revealed that Lucci can perform Life Return, like Kumadori, and use it to alter his body into forms that amplify his skills in a specific Rokushiki ability. However, only the Kami-e Form, which makes his man-beast form smaller and thinner, more like an average man-size, has been seen.