User blog comment:Kaido King of the Beasts/Chapter 885: The Whipping Boy's Nut Job/@comment-3177945-20171110192344/@comment-30395642-20171112121719

He is a unique type of paramecia because he can alter the shape of his body at will but attacks don't pass through him. He is using his remarkable observation haki to predict where opponents will hit him and is consciously moving his body out of the way but if he doesn't know an attack is coming it will hit him.

In chapter 884 there are several moments when Luffy is using Haki yet his attacks still seem to pass through him, because he's simply dodging.

It is similar to how Buggy separates his body to avoid attacks but because Mochi isn't very solid his body appears more liquid. He's not reforming he's just changing his shape. This is what they're talking about in 884 he even says he just changing the shape of his body to dodge attacks.

Maybe it should be a logia I personally believe that Blackbeards darkness fruit should be a paramecia but regardless of what we think it should be the official volume release of chapter 863 declares it as a special paramecia just like Blackbeards fruit is declared a special logia so that it what they are there is no getting around it.