Quote Originally Posted by Boa Hancock View Post
Instead of talking about Haki, let's talk about Devil Fruits. For starters, what are they?

The first possibility would be that he used his Kenbunshoku (CoO) Haki to sense the attack. It would have been fine, except that he never anticipated the attack at all, as evidenced by the line "So you two are Haki users."

The second possibility would be that Akainu has trained his Haki to the extent of applying logia defense unconsciously.
It can't be Busoshoku haki because Busoshoku haki hardens the user's body so that the attacks that are directed to them bounce off the user's body but akainu and aokiji were slashed by the WB pirates attacks.