The Water 7 and Enies Lobby arcs inOne Piece added a lot of lore to the series, and did a lot in particular to expand on the makeup of the World Government. At this time, it becomes clear that while the Marines are the main force the World Government uses to combat pirates, they also have a variety of Cipher Pol squads that conduct more secretive missions.
CP9, a squad of assassins, are the main villains in the Enies Lobby arc due to their intention to execute Nico Robin, who initially joins them willingly. The members of CP9 each have certain abilities which are unique to them, but all of them also employ a series of techniques known as Rokushiki.
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Each of the Rokushiki techniques grant their users superhuman abilities. Geppo, or Moonwalk, is a technique which involves kicking the air at superhuman speed to lift themselves higher, in what is essentially a form of flight. The technique works best using both legs alternately, but CP9's Fukurou has been seen using it with one leg being held onto. Restraining both legs renders the technique unusable. After the time-skip, Sanji masters his own versions of the technique, Sky Walk and Blue Walk, which work both in the air and underwater respectively.
Tekkai, or Iron Body, makes the user's body temporarily much heavier and much more durable to damage. Extremely strong physical attacks like Luffy's Gear Second can break through it, and the user remains vulnerable to non-physical attacks. The user is also unable to move while activating the technique, except for CP9's Jabra, who uses it in a form of kenpo. An unknown CP0 agent recently used Tekkai to interfere in Kaido and Luffy's fight on the former's behalf, weighing Luffy down and
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