"Looking for stability, one god was divided into Yin and Yang, the action of these two opposing forces created the world" according to the Tablet.
That could mean a great many things, however.
Was the Juubi the "One God" - or was the Juubi the Yin or Yang of said god?
The concept of the Taiji is that one existence defined as Yin and Yang. From the first interaction of Yin and Yang came microcosms of relative Yin and Yang which created the Eight Phases which in turn give rise to the mundane world that can be described with the tetragrams.
The God and the Yin and Yang described could be far more fundamental than such a mundane monster as the Juubi.
Or... perhaps the Ototsuki are somehow descendants of the Yang god and the Juubi is the Yin god? Thus, when Kaguya consumed the fruit, she was seeking to become like the "One God?"
That said, I like my idea that the Ototsuki and Uzumaki fought against Kaguya, developing the Eight Trigrams seal (as well as the Hyuuga's cursed seal) as a means of combating and ultimately sealing Kaguya. The battle left a contingent of the Ototsuki stranded - or, perhaps a contingent of Ototsuki stayed behind as guardians of Kaguya's fate.
I am also curious if something else happened to Kaguya.
In the story of the Bamboo Cutter - when Kaguya is to return to the moon (or sky) with her people, she forgets all of her sadness and concern for the people of the earth when a Hagoromo is placed over her shoulders and she returns to being immortal.
It was said that Kaguya wanted to end the conflict among the people... yet the character we see before us seems quite the lunatic (all puns intended), crazed with power for the sake of power. Hagoromo's telling of events makes -some- sense... people will lust after power to achieve a goal - they become misguided... but in Kaguya's case, it's as if her guidance shifted from "I will do anything it takes to fix problems" to "This next hit of power will blow chunks of my mind into outer space!!!!"
Perhaps you're catching on to my train of thought, here, Sir Derp... perhaps, even before Kaguya was sealed, something else was done to her. Perhaps there was another meaning to the tablet... One God (Kaguya) was divided into Yin and Yang.
Perhaps the Dead Demon Consuming Seal is one part of her... and whatever is chanting in Madara's head is the other.
Or... perhaps something else. Let's say Hagoromo divided Kaguya up into Yang (Wei) and Yin (Wu). Kaguya, as she became, represents force. Some other person, or entity, would be the essence of Yin, Wu - passiveness. Perhaps one guarded by the head family of the Hyuuga - the purpose of the Ototsuki remnant?
Of course... if that turns out to be the case, these forums will melt down after that chapter.
