Cipher Pol Aigis

CP0 is the strongest of all Cipher Pol units, even surpassing the assassination specialists of CP9. It is said the when CP0 is active, world shaking events are about to occur. Much is unknown about the agents and their abilities; however, the members of the group are shown to be masters of Rokushiki and are proficient in Haki as Lucci, Kaku, Stussy, Blueno and Kalifa learned Busoshoku and Kenbunshoku Haki. The agents who wear masks are among the most elite fighters of CP0, stated to be in a class of their own.

 

A masked member of CP0 is easily capable of defeating even an Ancient Giant. A group of masked agents consisting of Rob Lucci, Kaku and Stussy were referred to as Masked Assassins, but it is unknown whether this title is for masked agents in general. They work directly under the command of the World Nobles. They have strong intel over a myriad of subjects concerning the World Government, including the Artificial Devil Fruit Vegapunk created with Kaidou's Lineage Factor and X Drake's true allegiance. CP0 is in possession of at least one battleship, which was used to transport three of the agents to Dressrosa. The ship features the words "AIGIS" and "CP0" painted on the sails alongside the World Government insignia. The organization also summoned an entire fleet of ships in their mission to take over Wano Country, but it is unknown whether all of these ships belong directly to CP0.

One Piece Trivia

 The "Aigis" in "Cipher Pol Aigis Zero" may be derived from the Aegis, a mythological shield associated with Zeus and Athena shown as a short goatskin cloak. Athena's aegis is usually shown with a border of snakes and with the head of Medusa in the center. It is more an emblem of protection and power than an actual military shield.
    The three unidentified CP agents who met Carmel wear white outfits and tribal masks, features they share with most of other CP0 agents, although they are not confirmed as members of it.
    Kalifa and Blueno were originally not planned to be members of CP0, but Eiichiro Oda was convinced by the One Piece Film: Red staff to include them. However, Oda emphasized that the two do not wear masks, and are thus lower rank compared to the elite masked agents.
    CP0 is written as "CP AISIS 0" in One Piece Volume 777.