User blog comment:Black leg hunter/¨the Tyrant¨/@comment-3119203-20120127033427

Kuma is an OP mystery on par with the Void Century. At different points in his life, he has been a Revolutionary, pirate, and slave to the World Government. My best guess is that Kuma struck a deal with the World Government: they would spare some Revolutionaries or something on the condition that Kuma would obediently serve them. I don't know, so all of your guesses are pretty good.