Board Thread:Naruto Discussions/@comment-25369463-20140908104317/@comment-5423887-20141019222435

Reliops wrote: I think people assume Isobi has Crystal Release because coral being colloquially referred to as crystal makes about as much sense as acidic vapour being Boil Release.

Also, I'm 99% convince Gyūki has Storm Release. It just makes a ton of sense.
 * Ocotopi are water creatures
 * Lightning Release is common in Kumo
 * Madara using Storm Release as the Jūbi jinchūriki would make actual sense, like how Naruto could use Shukaku's Magnet Release

The only questionable thing about this to me though is, if Naruto had access to Gyūki's Storm Release, why would he incorporate ink in his jutsu? Doesn't make much sense.

edit; I find it puzzling people seem to ignore Kurama moulded wind chakra twice in the War Arc. His element is wind. Madara using Storm Release may be a feature of the Rinnegan. The Truth-Seeking Balls are apparently made of all the elements (basic 5 plus Yin and Yang), so combining two chakra natures seems well within the realm of possibility.