Bartholomew Kuma is a former Warlord of the Sea, the former king of the Sorbet Kingdom, and an officer and founding member of the Revolutionary Army with a bounty of 296,000,000. As a pirate, Kuma sailed the seas as a single-person pirate crew. He is also the adoptive father of Jewelry Bonney, daughter of his late friend and fellow revolutionary Ginny. Kuma is a member of the near-extinct special race known as the Buccaneers, inherited from his late father Clapp.
Because of the lies the World Government told the public, Kuma became feared as an extremely vicious pirate, earning himself the title "Tyrant". In exchange for curing Bonney of the deadly Sapphire Scales disease, Kuma became a special type of cyborg known as a "Pacifista", developed by the world renowned scientist Vegapunk. Once Vegapunk finished his modifications on Kuma, the Warlord was converted into the first complete Pacifista cyborg, with the serial PX-0, and mentally died in the process.Vegapunk also cloned Kuma as S-Bear, one of the Seraphim that were designed to replace the Warlords.
Kuma has been enslaved by the World Nobles twice in his lifetime: The first time was in his infancy until he escaped during the God Valley Incident and the second time in adulthood as punishment for the two years he spent protecting the Thousand Sunny and lasted until his fellow revolutionaries freed him during the most recent Levely.
While Kuma was presented as a major antagonist during the Thriller Bark and Sabaody Archipelago Arcs, he was secretly an ally and his action of separating the Straw Hat Pirates was ultimately done in their best interest, as it saved them from Admiral Kizaru and helped the crew's captain Monkey D. Luffy realize that his crew needed to become stronger; thus, Kuma played a key role in the subsequent timeskip. In his mindless state, Kuma is a major antagonist in the Marineford Arc where he took part in the Summit War of Marineford and sided with the Marines, along with most of the other Warlords, but he later becomes a major ally during the Egghead Arc and an important figure behind its ongoings.
Thirty-eight years ago, Kuma ate the Nikyu Nikyu no Mi, a Paramecia-type Devil Fruit that gave him paw pads on the palms of his hands; these paw pads have the power to repel anything they come into contact with. His paw pads grant him an absolute defense that allows him to protect himself from all physical attacks, even swords.
This ability, coupled with his vast reaction speed, allows him to repel attacks from extremely quick opponents, such as Luffy in Gear 2. He can also use his paws to attack by repelling his target at great speed. By Kuma's own admission, his paw pads repel things at the speed of light.
His palm strikes are able to deal significant damage to his enemies, due his repelling power subjecting his target to a severe level of force. Additionally, his power to repel is not just strong, it is also focused into a cannon-like blast, enough to create a deep hole through thick stone. His paw strikes can also travel beyond the target, dealing identical damage to anything behind them as well. Kuma can even repel the air itself, attacking his opponent with a cannon-like shockwave. He can also compress an immense amount of air between his hands into a single small bubble, and then release the air bubble, which explodes as a super-massive shockwave that can decimate an entire island.
Interestingly, he can repel all the pain, injury, and exhaustion out of a person's body, allowing him to completely heal people in an instant, even if they have suffered an incredibly severe level of damage. Once the pain is expelled from the person's body, it takes the form of a paw-shaped bubble, the greater damage that was removed, the larger the bubble will be. The damage can be transferred into another person's body, causing them a great deal of suffering all at once.
Possibly the most impressive application of this fruit is that Kuma can send someone flying over vast distances, even across the world and traveling over the course of several days. The victim of this ability is encased in a paw bubble that protects them from and breaks through any obstacles that are in the way of the destination of Kuma's choosing. To an outside observer, the victim appears to vanish.
Kuma is now a cyborg modified by Vegapunk. He is, however, very different from other cyborgs, and displays strength and agility that are on a different scale.
As with the other Pacifista models, Kuma has a built-in electronic recognition device within his pupils, which enables him to accurately identify certain individuals (presumably anybody that is listed within the World Government's bounty system) and their bounty count from across a distance of several dozen meters. Kuma is also equipped with augmented hearing, allowing him to pick up any sounds at a greater range than normal.
Kuma's massive build along with his cybernetic enhancements grants him tremendous durability and strength comparable if not superior to other Pacifista; the average Pacifista model is capable of withstanding a combination assault from the pre-timeskip Monster Trio. At Thriller Bark, he effortlessly lifted a large slab of rubble with a single hand and his body was resilient enough to withstand most physical attacks, including Sanji's "Concasser" (in fact, Sanji injured his leg after delivering the blow, despite it being strong enough to stun a user of Tekkai) and even Zoro's "Shishi Sonson", a technique that was able to cut through steel, which only left a scratch on Kuma despite it being a surprise attack. Emporio Ivankov's "Galaxy Wink" appeared to inflict no substantial damage upon Kuma, despite the barrage of attacks being powerful enough to knock him off his feet.
Even after two years of accumulated damage, lack of repair, and lack of sustenance intake, Kuma was still operational. While the modifications gave Kuma great strength, their full completion over a long time period apparently robbed Kuma of his free will.
Due to technically having his mind removed, Kuma does not feel any pain. While being enslaved by the World Nobles, Kuma was constantly and brutally abused by the World Nobles without feeling any discomfort, not even reacting as Rosward struck his head hard with a hammer and stabbed him with a sword. He has multiple swords stabbed inside his body and continues to function without succumbing to the accumulated damage.
As a Pacifista, Kuma has the ability to shoot laser beams, which not only causes massive explosions upon detonation, but can also melt steel. This laser is apparently a replication of Kizaru's Pika Pika no Mi powers and for Kuma, this launcher is only installed in his mouth. In the other Pacifista, the launcher is installed on their palms as well. Kuma has his paw pads instead of the laser holes on his hands; it is this aspect, along with the bible that only he holds, even after losing his free will, that distinguishes him from the other Pacifista, and makes him superior to them. However, he seems to possess gloves that allow him to shoot lasers from his palms, as he was about to demonstrate during Charlos's second attempt to kidnap Shirahoshi.
Kuma possesses the ability to use Busoshoku Haki and can utilize it to harden his fist, boosting the power of his punches. With one Haki-infused punch, Kuma was able to knock Jaygarcia Saturn off his feet and send him crashing into several buildings.