Board Thread:Theories and Speculation/@comment-1512913-20161105081557/@comment-734582-20161105200328

Enpai wrote: It is actually impossible to describe the origin of the Demonic Statue while matching the canon because the manga blatantly contradicts itself, so I guess they didn't even bother to try. It doesn't contradict itself. SP:CT splits body and soul, so to speak. The body, the Gedo statue, was sealed in the moon. The Juubi's chakra was ripped out. Considering that even the chakra of such a beast would still be a huge problem, Hagoromo sealed that chakra inside him, becoming the Juubi Jinchuriki.

On his deathbed, Hagoromo summons Gedo (explaining why there's a connection at all between the Rinnegan and Gedo). He absorbs it and splits the biju. Probably because he wanted to survive long enough to teach and talk to the Biju.

Then, he reseals the Gedo inside the moon with a new Chibaku Tensei.

This resolves all seemingly contradictory statements neatly into one account. It's possible Hagoromo needed Gedo for its life force, in order to give individual life to the Biju. But that's more speculation than i want.