Board Thread:Naruto Discussions/@comment-25369463-20140908104317/@comment-1512913-20140910090246

Madara using Storm Release is the very damn reason why I still believe each Tailed Beast having an advanced nature to be possible and true.

For Gyuki, I don't think it has Storm Release, but Explosion Release, but that's just me. Also remember this: the core was coated with the ink, so it's possible the nature was under the ink and we just didn't see it.