Nero

Known as the "Nero the Sea Weasel", he was considered the newest member of CP9. He was first introduced on the Puffing Tom, where he was helping to escort Nico Robin to Enies Lobby.

Abilities and Powers
As Nero is still a new recruit, he only mastered four of the six Rokushiki techniques of the CP9 unit: Soru, Geppou, Kami-e, and Rankyaku. His lack of Tekkai and Shigan makes him unable to block powerful strikes and pierce opponents, respectively. To compensate, he evades enemy strikes carefully with Soru, Geppou, and Kami-e; for offensive, along with slashing with Rankyaku, he uses pistols instead of stabbing with his fingers. It also seems that his Rokushiki isn't that powerful since his Soru was actually a fast run, rather than disappearing speed.

Nero may not be very strong compared to the other CP9 agents, but he was still a keen analyst and strategist, making him a formidable foe. He figured out all on his own that the attackers on the Puffing Tom would try going along the roofs of the train cars in order to reach the one containing Nico Robin as easily as possible, and he was able to quickly deduce that Franky was vulnerable to attacks aimed at his back.

Regardless to his clever improvising and analytical nature, his lack of mastery caused Rob Lucci to claim Nero was not qualified to be a superhuman, and was "worthless" to the unit.

History
Nero attempted to stop Franky from rescuing Robin but failed and was punched through the roof of Puffing Tom, into the room where the rest of CP9 was. Nero then continued to try to fight Franky and stated he would kill him, but Lucci wouldn't allow this, as they were simply supposed to be capturing him. Lucci then gave Nero three seconds to escape, at which point Lucci quickly took him out with five Shigan attacks. Lucci then personally expelled him from CP9. It is unknown whether or not Nero is dead or alive, as Lucci is a very skilled, shoot-to-kill sort of person, and Nero's limp body was thrown into the ocean during Aqua Laguna, one of the biggest storms in the world.

Trivia

 * He has a weasel theme, due to his nickname, whiskers, ear-like hair, and tendency to say "shao" (a weasel noise) when he speaks.
 * In a recent Weekly Shonen Jump, in a poll to determine the most popular One Piece characters, Nero ranked at 98th.
 * He and Fukurou are the only CP9 members to have an epithet.