Sasuke and Itachi may have had the eyes, but they didn't have the chakara levels that Madara and Obito possess. But when Kurama said Sasuke's chakara is similar to Madaras, it's still not exact and we all know the amount is no where close.
could rikudou's brother have written the tablet?
we know the tablet speaks of killing....and rikudou just made it clear he had nothing to do with ninjutsu
The Sage did Write the tablet. Why he wrote, to leave a record of his history behind and a explanation of his era and intended system of Ninshu. The Tablet is almost a diary or Journal RIkkudo Sennin.
The Tablet primarily explains that Kaguya eats the Forbidden Holy fruit and tamed the known warring world; Gave birth to a child or children. She dies and The Holy Tree becomes the Jubbi to reclaim its chakra; Her son fight and seals it within himself saving the world. He then spreads the teaching of Ninshuu to create peace. People however use this to power to fight wars and create ninjutsu. The Savior of the world Has two sons who inherit his god like powers. They eventually form a rivalry because of their fathers appreciation of the younger, weaker brother methods. Rikkudo Sennin divides God Tree/Juubi into 9 entities and seals it's original form as the moon. The children of the Sages wage war against each other and become the ancestors of Senju and Uchiha.
That's pretty much what's on that tablet. Unfortunately the only way to read all of this and gain all of this information is to combine the bloodiness of the Rikkudo Sage.
kept telling you guys...that the sage couldn't have written how to do MT
plus,the killing of a close friend/relative shit...it all just went against everything we heard about him
As for Kurama being controlled by MS. It would have to be a combination of Chakra & Eyes. Since Susano'o can wrap around Kurama and fit perfectly, It says a lot about the compatibility of chakra.. Otherwise Kakashi could have controlled Kurama too!
In addition, At the start of Shippuden/ Part 2 It shows Sasuke keeping Kurama at bay using his chakra in naruto's subconscious. Kurama then stated it was his "Sinister Chakra".
In the future we will see perfect Susano'o and Naruto in Ashura Bijuu mode, Combined to some ridiculous Giga-Giant that will be fighting Kaguya in her Juubi Bijuu mode with zetsu darkness attached!
This will create the opening for Naruto and Sasuke sealing her.
Will be coooooooooool.