The other day, my friend brought to my attention the fact that Tobi can possibly be the oldest son of the sage of 6 paths.. It is known that the sage eventually chose his youngest son (Inheriter of his will of fire, body, & physical energy/senju clan) as his sucsessor instead of his oldest son ( Inheriter of his eyes & powerful chakra/Uchiha)..The eldest son got mad & eventually waged the 1st ninja war against his younger brother..It is known that the sage of 6 paths had MANY followers..so he was like a king giving the throne to the youngest..this gave the youngest brother an army full of followers..While the eldest brother had nobody on his side. However the sage had an eye technique called "the creation of all things" which he used to create the tailed beasts & other shit..he also used it to lock away the body of the weakened 10 tails within the moon..I think the eldest son (realizing that he needed to quickly gain an army to face his brother) possibly performed an imperfect version of that eye technique & created the Zetsus.. I think the eldest lost the war, but was then revived by zetsu.. The sage of six paths ( before his death) created a stone tablet which contained details of his life & the secrets behind the 10 tails. but only those with a rinnegan could decipher its messages. After being revived.. The eldest son (im just going to call him tobi from now on) wanted ultimate revenge. Somehow..using his rinnegan, he found & read the hidden tablet & later devised the "moon's eye" plan which involves reconnecting all of the 10 tails seperated chakra(1-9 tailed beasts) & store it back into the 10 tails..& also controlling the MOON, where the 10 tails body is so coincedentaly stored..But his weakened body would not be enough to face the jinchiruki's on his own so he forced the formation of Akatsuki(who's ultimate goal was to gather all jinchiruki) & stored his eyes in Nagato to better disguise his identity. then later get it back..All in all, I believe that no one other than the eldest son of the sage of 6 paths would know about all of this stuff about gathering the tailed beasts & where its body is hidden. & he wants revenge on the whole ninja world who never took his side. including senju & uchiha decendants...(MY OPINION) i dont need all of that negative ish -_-