Board Thread:Naruto Discussions/@comment-3279282-20140828133937/@comment-24934641-20140828184232

@Archangel

I've been wondering that for a while, myself. I think there is an answer. In this chapter the beasts (Juubi's chakra) were removed, leaving the Gedo Mazo/Kaguya to be sealed. I believe this means that in the past, Hagoromo basically become the host of the Juubi's chakra, while he sealed the body into the moon. Near his death, he finally created the Biguu by splitting up the chakra. The only inconsistency I can see with this theory is that Hagoromo survived the extraction without the Gedo Mazo. However, he was dying anyway, so maybe he just used his senjutsu chakra to last long enough to name the Biguu.

Overall, the main problem with my theory is the fact that Kurama hinted that Hagoromo still had the Gedo Mazo in Chapter 656.