User blog comment:Kaido King of the Beasts/Chapter 884: Sing or Swim/@comment-31429799-20171103140934/@comment-30395642-20171103215256

He is physically turning into Mochi in order to change the shape of his body. Multiple times he has been shown with holes in his body or being split in half, even after Oda changed it to a paramecia type. But the way I see it is the attacks aren't passing through him like they would with a logia user, instead what he's doing is creating the holes in his body so the attacks miss him completely. It is similar to Luffy stretching his body out of the way of something but because Mochi is far less solid than rubber is his body is more viscous and it looks like the attack pass through him.

He also appears to be able to store things in his body as at the end of chapter 881 he pulls his trident out of his own arm, splitting his hand in half as he does it. It is definitely very similar to a logia but I think the key difference is that attacks don't pass through him he has to consciously alter the shape of his body to allow the attacks to miss. Hakiless attacks would still hit him if he wasn't moving out of the way.

It is different to Trebol who wasn't made of mucas and was just coating himself with his power to look bigger so that people would hit the wrong part. Katakuri is made of Mochi and can move his body like a liquid because Mochi is a little viscous.

In many ways it's the exact opposite of Blackbeard's power which is a logia that doesn't allow attack to pass through him.