no other than OROCHIMARU. He is the main protagonist after all. He obtained the Rinnegan and the Sharingan because of his experiments. Can't you see, TOBI created ZETSU which is from the the FIRST HOKAGE and it has been observed that in some parts of the manga OROCHIMARU is using the 1st's blood in his experiments. and now kabuto cited "i am his assistant". What does that mean? of course it's because he is assisting OROCHIMARU all throughout the war. and also, he's the shinobi obesesed with the power of the UCHIHA. why? because in the end when you possess the mangekyou sharingan the next will be the rinnegan! and that's OVERWHELMING!
qraq ur wrong....... Obito's good eye may
have survived as u say but he didnt have a left
eye anymore and TObi had his left eye and used it
to use izanigi against konan. second Tobi is not
Obito rearranged lets count TOBI 4 letters OBITO 5
yea not a rearrangement by logical standards. 3rd
ur whole aging theory is stupid bc if he is
traveling thru dimensions with no relative time or
space he wudnt age at all meaning he wud still b a
kid bc no time and space means tht time doesnt not
pass in any manner.