Board Thread:Naruto Discussions/@comment-25369463-20140908104317/@comment-4912646-20140910031851

RexGodwin wrote: why is everyone saying Isobu has crystal/ice? lol we've seen it uses Coral, thats it.

Process of elimination. None of the others seem fit for Ice (or Crystal), and a lot of people including myself want the theory of each tailed beast having one "advanced" nature to be true.

I originally thought that all the kekkei genkai ninja could be explained as descendants of ancient jinchuriki or something along those lines, but chapter 688 pretty much crushed any hopes of those theories for me. Unless ink and bases are the last two unrevealed natures (which would require Blaze not being a normal combination), it would be weird for some tailed beasts to have a unique substance/ability and an advanced nature (Isobu having coral and ice, Kurama having emotions and ???) while others have just an advanced nature (Son Goku).