This will be more to read than a lot of threads, but please bear with me, you will be happy you did, even if you disagree with me. Thank you for reading.

Flash way back to the battle between Madara and Harashima. We know that Madara survived that battle, barely alive, and since that battle, has been stuck to the Gedu statue this entire time, until meeting Obito. When Obito arrived, Madara told him, that he just appeared in the cave suddenly. You may say that Madara brought him there. However, this is EXACTLY what happened to Madara after his battle with Harashima There were both on the verge of death, and was transported to the Gedu statue.

So, who brought both of them there. I believe it is the remaining essence of the 10-Tails, after the SOT6P took its chakara and divided it 9 ways, trapped within the Gedu statue. However, when the SOT6P sealed the 10-Tails, the Senju side of him used for the seal, unintendedly resulted in the sprout. Thus, ZETSU was BORN.

The 10-Tails is obviously upset, and will stop at nothing to become whole again. Suck in a statue, with its only connection to the outside world being a comparatively weak parasitic clone. The 10-Tails faced a dilema, the only person able to make him whole, the SOT6P is now dead. The 10-Tails knew that the Uchia and Senju blood line together, was the only way to obtain the Rinnengan. After waiting generations, the 10-Tails found its opportunity. He saved Madara from death, and used Zetzu to copy the chakara of both Madara's and the remaing traces of Harashima. Now having the copied chakara, the 10-Tails has the ability to create the rinnengan. Prior to this Zetzu just observed the world, learning the secrets of all the nations. Including the incredible chakara of the Uzumaki clan. Now, the 10-Tails is keeping Madara alive solely to continue using Madara's sharingan. The 10-Tails is now able to go out and try to get control of the tailed beasts, by putting in motion, the formation of Akatsuki. I believe that the secret behind the Uzumaki clan, is that it could possibly be a dilution of both the Uchiha and Senju blood lines. It would explain how Naruto appears to use abilities of the SOT6P. It is for this reason the 10-Tails chose Nagato to wield the Rinnengan. By doing this the 10-Tails has the man power and key through the rinnengan to start capturing the transferring the chakara back from the Bijuu.

Now to put this in perspective. I am saying that Madara has his goal, and Obito has his goal... BUT... so does the 10-Tails...

Well how about it? What are your thoughts?