Kuma will meet the Saddest Death in One Piece
Kuma’s backstory is one of the most tragic in the series. He is a member of the near-extinct special race known as the Buccaneers. Four years after his birth, government agents tracked and captured his family, enslaving them to the World Nobles.
As Kuma grew up, he and his family were severely abused to the point that his mother died and he wished for death as well, but his father begged for him to endure. To cheer Kuma up, his father Clapp told him about the warrior of liberation: Nika, that would one day rescue them from their imprisonment. Clapp sung Nika‘s rhythm for Kuma before he was shot and killed by a noble.
Kuma finally managed to escape during the God Valley Incident. At 17 years old, Kuma became a priest, spending his sundays helping the elderly population of a nearby village by literally taking in their pain every week through his Devil Fruit abilities, with Ginny taking care of him every time he did so.
While Kuma had feelings for Ginny, he refused to accept her marriage proposal due to what happened with his mother, who was enslaved solely for having a buccaneer husband. At a certain point Ginny was captured by the World Government and became a wife to a World Noble. After contracting the Sapphire Scales disease, Ginny was released from slavery and used the little time remaining to her to return to the Sorbet Kingdom with her child, dying as a result.
After mourning her death, Kuma swore he would adopt Bonney as his daughter and take care from now on in order to honor Ginny’s memory.
Because of Bonney’s condition, Kuma was very protective of her. The reveal that his daughter would likely die before she could enjoy life, however, left him heartbroken.
At a certain point Kuma was once again enslaved by the World Nobles. Heis now a human weapon called a “Pacifista”, developed by the 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.
Remember Kuma sent himself away from Mary Geoise some chapters back after Akainu took off his leg and half his face (sans Whitebeard). Oda is going demon mode on the feelings and I can see Kuma teleporting to Egghead, absorbing his memory bubble that Vegapunk has kept and regaining his humanity for just a few minutes.
One leg, half a face.. he smiles weakly at Bonney and uses the last of his strength to do the Nika dance his father did for him when he cried….. Bonney sobbing as Kuma uses the last of his life force to send Bonney and everyone away on the Sunny towards Elbaf as he gets finished off by Saturn.