**When u think about it, at lougetown, when smoker almost got luffy, a massive wind blast swept the whole streets that could have only been logia potential.Even smoker knew it would blow him away as he's a smoke user
And the whole wind blast lookd kinda green which could have hinted its not a normal type of wind and also dragon was the only person unaffected by it so he might have eaten the Kaze Kaze no mi (wind wind fruit).
Add ur comments as this is just a theory.. An well.. Be cool**