Yasaka Magatama

Using the complete form of Susanoo, the user is able to create the Yasaka Magatama between two of its arms, consisting from a number of tomoe bound together through their respective centres by a single thread of chakra. Due to this structure, the tools then act in a similar manner to that of a shuriken when thrown by Susanoo, rapidly spinning towards the intended opponent until they eventually collide.

Itachi Uchiha
In Itachi's version, three tomoe are bound together by a single circular thread, after being created by the right arms of his Susanoo. The entirety is then thrown towards the target as a single projectile, which Itachi asserts to be his strongest long-range technique.

Madara Uchiha
In Madara's version, a considerable number of tomoe are strung out between two of his Susanoo's hands, using an interconnecting thread. When thrown, the entirety detach from one another, with each individual tomoe becoming a separate projectile instead.

Ryun Uchiha
In Ryun's version, a large amount of tomoe are generated in a halo-like formation around his Susanoo; strung together by an interconnecting thread of chakra. When thrown, the tools can function as one large attack, creating a massive explosion on impact, or break apart into individual tomoe to be used for separate attacks.

Influence
The Yasakani no Magatama (八尺瓊曲玉; lit meaning, "Eight Shaku Curved Jewel") is one of the Three Imperial Regalia of Japan (三種の神器, Sanshu no Jingi), together with the [[Wikipedia:Kusanagi no Tsurugi|Kusanagi no Tsurugi and the Yata no Kagami.