Pacifista

The Pacifista is a project of creating a human weapon, in the form of a cyborg. The Shichibukai Bartholomew Kuma is incomplete model as well several of his replicas.

Appearance
All the Pacifista other than Bartholomew Kuma seen thus far have been identical in appearance to him, even in his uncommon body proportion. Pirates who seem them believe it being Kuma himself. Kuma replicas are very calm and silent, however they also become uncontrollable.

Abilities and Powers
The Pacifista are cyborgs much like Franky of the Straw Hat Pirates. They have a body made of an unknown substance tougher than steel (as Zoro couldn't damage Kuma), however as Franky pointed out though they are equipped with various body modifications, also like him they are still human and they are capable of bleeding.

As cyborgs, the Pacifista are capable of taking staggering amounts of damage and continue to opperate afterwards while fighting many strong foes all at once.

They are capable of firing a beam from their mouth and hands (with exception of the real Kuma which the Devil Fruit Nikyu Nikyu no Mi cover the palm of his hands) which are replicate to the Kizaru's Devil Fruit.

As pointed out by the Straw Hats, the lack of the Devil Fruit ability doesn't make them less powerful then the original Shichibukai.

Bartholomew Kuma the Pacifista
After Kuma witnessed Moria get beaten by Luffy, Kuma then reported this to the World Government. Fearful that the rumors of Gecko's defeat will cause another global uproar like with Crocodile, they ordered Kuma to kill all witnesses on Thriller Bark including the Straw Hat Pirates. Accepting the order, he launched an attack on some of the members of the Thriller Bark Victim's Association before shifting his attention to Zoro. Kuma weakens Zoro, and uses his Devil Fruit ability to take down Franky and Sanji. He gives them an ultimatum: let him kill Luffy, and he lets them live. When they refuse him, Kuma calmly detonates the entire island.

Though this does not succeed in killing the Straw Hats, it knocks all of them out. Just when he is about to finish an unconscious Luffy off, Zoro, in a desperate move, strikes him with a Shishi Sonson (Lion's song) in an effort to kill him by cutting him in two but is only able to damage him. The wound on Kuma's shoulder reveals that he is a Cyborg. He then reveals that he is different from Cyborg Franky. Kuma is an incomplete human weapon created by the World Government and Dr. Vegapunk, known as a Pacifista. Zoro offers to trade his life for Luffy's, seeing no other way. Kuma agrees and at that moment, Sanji decides to give his life up. Zoro promptly knocks him out, feeling necessary to sacrifice his own life rather than Sanjis'. Kuma states that he would not harm Luffy, as his "honor would be at stake", in exchange for Zoro experiencing the pain Luffy endured throughout his fight against Moria. Kuma proceeds to literally extract Luffy's pain, and directs it to Zoro, which almost kills him. Kuma then teleports to the entrance to the ship. He is last seen musing about Dragon, having a good son with a loyal crew.

The Pacifista attack!
Soon after, many other Pacifista units made their way to the Sabaody Archipelago, where one of them was able to track down and find the escaping Kid Pirates, who were running from other Marine chaos due to the actions partially caused by captain Eustass Kid. The Heart Pirates soon joined in the battle to escape the island.

Also, another Pacifista appeared in front of Urouge and a third in front of the Strawhats. During the recent battle, they demonstrated none of the Devil Fruit abilities the original Bartholomew Kuma had previously, firing lasers from his hands instead of using his paw fruit, and failing to counter Franky's coup de vent, despite his previous fighting style being heavily focused on reflecting air. It was X. Drake determined that these many Kumas are in fact Pacifistas, into which Vegapunk has copied Kuma's appearance and Kizaru's powers.

Trivia

 * The ideas behind the Pacifista are likened to the ideas of the The Terminator. In the movie (and its sequels), the Terminator machines were designed to be ruthless robots that were machine on the inside but on the outside looked human.  They were able to use any weapon and took huge amounts of damage before finally being shut down.  Their human appearance (a strong, emotionless soldier) was replicated across all Terminator units.  The idea was so that the humans they were hunting would know what they were upon sight and the machines appearance would strike complete fear into them making for a much easier kill.