User blog comment:Monkey.D.Me/HAKI X haki = ???/@comment-3119203-20120104202214

No fourth type of haki, but think of the haki thing this way........if a person takes an iron bar and hits it against a wooden pole that another person is holding, which one will break? The wooden one, because, it is weaker. But keep in mind the haki doesn't have to be stronger, there are certain weapon-breaking techniques that we have seen Zoro and Ryuma use.