If Vegapunk was able to literally cut his brain into pieces and put it into 6 different bodies, could that procedure have done to others?
Talking specifically about Bartholomew Kuma. What if Kuma’s original body is now a hollow vessel and his real brain was transplanted into another body? A stronger version… maybe into Kuma’s own Seraphim?
That would explain why he is acting weird. It would explain the robotic personality of the original Kuma because Vegapunk just put a robotic brain into that body so that the World Government could do with it whatever they liked while (unknowingly) leaving the real Kuma free.
Now after he and Bonney meet back up she can age the Seraphim Kuma back to the age he is supposed to be making him the strongest Seraphim of them all. As it was stated that Jinbe Seraphim was weak due to his age. Later on Lucci and other members of the CP0 might blackmail Bonney into aging some other Seraphim by threatening to kill Kuma. Making the Seraphim a force to be reckoned with.
*Theory by Ensushalame