Cipher Pol is a series of World Government organizations. They act as secret agencies who do investigations, assassinations and espionage for the World Government.
There are eight official Cipher Pols that are numbered from CP1 to CP8 with two unofficial units, which are named CP9 and CP-0.
CP-0 is the strongest of all Cipher Pol units, even surpassing the assassination specialists of CP9. It is said that nothing good can come from this group’s presence as stated by Robin. They work directly under the command of the World Nobles.
Then we have SWORD, the Marine Headquarters Top Secret Special Force led by X Drake.
Their operations involve undercover missions to monitor Yonko activity. Koby and X Drake were shown contacting each other to brief on urgent developments.
They are not informed of World Government operations and their covert activities. We also know that they use code words to verify secure channels. I’m sure that SWORD is unknown even for the Gorosei. Kizaru was not aware of Drake still being part of the Marine at Sabaody. He is an Admiral and was still not aware of this organization.
Their name, SWORD, contrasts them with CP-0, whose full name is Cipher Pol Aigis Zero. The word, Aigis, comes from the Aegis, a shield in ancient Greek mythology.
This could be a hint for a future separation of some heavy members at Marine from World Goverment’s politic actions. Fans have speculated that also Sengoku, Garp and Aokiji might belong to this Secret Special Force. They eventually disagree with the system and how things are run. They don’t believe in Absolute Justice but Moral Justice.
This leads us to the question: will there be a clash between SWORD from Marine and CP-0 from World Government?