Why did Bartholomew Kuma allow Vegapunk to turn him fully into a pacifista? Kuma seems to have a good enough relationship with Vegapunk. Vegapunk was able to grant him his final wish as a human being, which was to program Kuma to protect the Straw Hats ship until their return. It is very likely that Vegapunk highly respects Kuma's strength, as he modified Kuma to be the prototype Pacifista, and he let Kuma do things that go against the World Government, as well as granting him his last wish by including a mission into his programming that Kuma himself had requested.


It is even shown that the bible he holds is his trademark. If that is true why would he sacrifice his consciousness along with his humanity if he lived life cherishing something that very much so represented humanity, freedom and free will?

If he much admired the prospect of free will, going as far as wanting his last wish to protect the Straw Hats ship, why would he even agree to losing his humanity and getting modified to a fully-fledged Pacifista?

Is it ever mentioned or is it just some extremely personal relationship stuff shared between Vegapunk and Kuma?
An explanation is that after rescuing straw hats at sabaody, he was defeated by Kizaru and captured in seastone cuffs. After that he probably received death penalty, but since hes a pacifista project he was probably sent to vegapunk to have his brain removed.

His capture and punishment was not mentioned somewhere in the manga/anime. 

However, this is a VERY PLAUSIBLE theory on why Kuma was turned into a full pacifista. Certainly a more plausible theory than the 'he did this for dragon', or 'dragon ordered him to do so' nonsense theories that are floating around in this discussion, neither of which are mentioned anywhere in canon either.

It is highly unlikely Kuma was willingly turned into a full pacifista. Some people posted here that 'he did this for Dragon', 'Dragon ordered him to do so'. What? How would doing so benefit Dragon and revolutionaries? How would it benefit Kuma himself (obviously won't since he would be dead?) What other POSSIBLE incentive that world govt offered him or the revolutionary that could be so great, that it would outweigh the consequence of him being dead? Probably none. Therefore it leads to conclusion that the government forced that choice upon him. Straight up executing him most likely wouldn't have been an attractive option, since they would need as many shichibukai on their side to face against whitebeard. Therefore all these points toward my theory - that Kuma was punished for opposing the marines and an admiral from carrying out the order to purge the tenryuubito's attackers. Thats why world govt most likely decided to fully transform Kuma into a pacifista in order to both punish him and turn him into a fully loyal slave.

Kuma was certainly aware that this would be his punishment, thats why he stated that this will be the last time he will meet the strawhats.

Vegapunk most likely was in a good relationship with Kuma and likely did not want to turn him into a full cyborg either, but he had to do so under the pressure from the world govt. Thats why Vegapunk likely programmed in Kuma's request to protect the Sunny.