Board Thread:Naruto Discussions/@comment-25369463-20140908104317/@comment-4912646-20140910035919

Aka Shi Crow wrote: Scale Powder would be also part of 7 tails body like Ink from Gyuki, trying to give those techniques a type of Release is wrong,they are unique

True, all the remaining substances we've seen do seem to derive directly from the tailed beast's body, unlike Shukaku's magnetism, Son's lava, and Kokuo's steam (possibly Boil Release). Shukaku could actually be an example of this, since he seems to create new sand from his own body rather than creating it out of existing earth like Gaara does, and Magnet Release probably doesn't create sand on its own. It just seems unfair then that some tailed beasts would get a unique ability and a nature while others are stuck with just the latter.

It also doesn't explain why they didn't add their supposed natures to the Rasenshuriken. It was Kishimoto's perfect chance to reveal them all.