Uchiha

Having had a considerable gain in information Shikamaru next infiltrated the Uchiha, he was relieved to find that his shadow history technique would let him bypass the Uchiha scrolls requirement of needing the Sharingan to read, after absorbing every speck of knowledge in the clan he found records of the clans origin, he proceeded to the Naka shrine and found a stone monument in the main hall beneath a tatami mat, here was where all his questions were answered.

Shikamaru had to drain almost all his Chakra which had risen to Low-Kage levels in order to gain the complete history of the monument, stated three were the secrets of the Mangekyō Sharingan, such as instructions on how to obtain it, and its ability to control the tailed beasts the actual history of the world involving The story of the Sage of Six Paths, Kaguya and the God Tree, Warnings regarding Kaguya's Infinite Tsukuyomi, The Uchiha would be saved by the Infinite Tsukuyomi which were most probably a manipulation by this half dark half white creature to cause the Uchiha to proceed with Kaguya's plan and there were also secrets of the Uchiha clan and Warnings about the misfortune that Sharingan can bring.