Board Thread:Naruto Discussions/@comment-25139119-20140705022956/@comment-1512913-20140804125020

We know well what they are made of, the Ten-Tails' chakra, that's it. What nature transformations they use is situational, not mandatory. In case of Obito's usage they were "at least 4 natures" and then also YYR.

Naruto's TSB are simply Wind Release, proven when he expanded one and threw as Tailed Beast Ball Rasenshuriken.