Board Thread:Theories and Speculation/@comment-25093611-20160304230401/@comment-734582-20160311174242

GreatestSin wrote: 2. even if he can do it, why should he waste chakra on air-walking if he can kick it and accelerate himself without it? I think Eight Gates simply enhances your body with chakra. It allows your body to go to unnatural limits. It doesn't give you unlimited chakra. Guys techniques aren't even chakra based techniques, Kisame thought Hirudora was chakra but it's not, it's pure air.

So Guy can't use chakra to walk on air because that's not how Eight Gates works. Even things like the Red Dragon aren't chakra avatars. It's pure raw Taijutsu.