Board Thread:Theories and Speculation/@comment-26422475-20181104100351/@comment-734582-20181117195404

Elveonora wrote: Come on folks, you truly do believe that Tailed Beasts are just pure chakra given form? No. I'm using it to hammer home that we're clearly not being told everything, not regarding Biju or Chakra, and that Kishimoto's being unnecessarily vague about it.

Biju have souls, since Reaper Death Seal works on them. So that makes biju ... sort-of-Edo Tensei? There seem to be quite a few similarities between biju, Edo Tensei and what Obito and Dan did (IE a soul possessing a body willingly).