User blog comment:Dany1459/Doflamingo's Abilities/@comment-71.250.198.157-20120629031051

I believe it is the string string devil fruit. ~ plain and simple

Example: When Doflamingo cut off Oars Jr.'s leg, it was a clean cut; which only can be induced by a sharp narrow string/thread or sword with extreme force. A sword is definitely out of the question unless it is invisible, this is how I reached my conclusion.

I have strong faith that I am correct, but can only wait until they reveal his "ability" in the future.