Susanoo

Susanoo is a technique that creates a spiritual being resembling a yamabushi. Itachi's version wields the sacred, a mirror that's considered one of the three sacred treasures capable of reflecting all attacks, as a shield in its left hand. In its right, the legendary, also known as the , is held. The Totsuka no Tsurugi, commonly sheathed in a sake jar held by a third hand growing from Susanoo's right forearm, is an ethereal weapon with an enchanted blade capable of sealing anything it pierces in a "world of drunken dreams", sealing them for all eternity, and is described as the perfect counter to Orochimaru's Kusanagi Sword. Like the Amaterasu and Tsukuyomi, Susanoo is an ability of the Mangekyō Sharingan. Zetsu said that Susanoo's Totsuka Sword combined with the Yata mirror essentially makes Itachi invincible, and has thus been labeled as the "Raging God of Battle".

The Sword itself can be presumed as an extension added to the technique as Zetsu mentioned that no matter where Orochimaru searched for it, he could never find it. It is also possible the Mirror can be another extension, as Zetsu also mentioned that it is another legendary item, on par with the Sword.

Sasuke has also been shown to be able to use Susanoo, which he can skillfully manifest as a mere ribcage around himself for a strong defense or a larger form capable of attacking others. He at first uses it to protect himself from the Fourth Raikage's Liger Bomb. Though Sasuke managed to survive the impact, two of Susanoo's rib bones snapped. Sasuke has also combined Susanoo with Amaterasu for defensive maneuvers, wrapping himself with the black flames of Amaterasu as a shield while protecting himself from it with Susanoo. When Sasuke was attacked by Gaara, Temari, Kankurō, and Darui simultaneously, he appropriately manifests a more complete version, with the skeletal muscles. Sasuke's version is slightly different in appearance, the horns being the most noticeable difference as well as having a darker, evil looking aura surrounding it. It wields a blade in its left hand; whether this is the Totsuka Sword or not is yet to be confirmed, but it is strong enough to shatter stone pillars and cause a ceiling to cave-in in one strike. However, Sasuke's Susanoo did not provide the same durability as Itachi's, as the rib bones are snapped by multiple attacks from the Fourth Raikage, and melted by the Fifth Mizukage.

Like the other Mangekyō Sharingan techniques, Susanoo comes with its own risks. To sustain Susanoo, the user must act as a medium for the spirit, allowing it to consume their life force energy. This puts a severe strain on the user's body. Even while using Susanoo in its "imperfect" form, Sasuke describes it as feeling pain in every cell in one's body. Prolonged use will lead to the user's death. When Itachi was closer to death, his Susanoo was falling apart, with the armor disappearing, then the skeletal muscle, and so on. According to Madara Uchiha, for a Sharingan user to activate the Susanoo is a rarity.

Influence

 * Similar to other Mangekyō Sharingan abilities, Susanoo was taken from Japanese mythology. Susanoo, the god of sea and storms, was the brother of Amaterasu and Tsukuyomi, with Susanoo born from Izanagi washing his nose.
 * The Totsuka Sword is the sword used by the god Susanoo to slay the eight-headed and eight-tailed snake, Yamata no Orochi, just like it was used by Itachi's Susanoo to defeat Orochimaru's.
 * The is one of the, together with the  and the Yasakani no Magatama (八尺瓊曲玉) Jewel necklace.
 * The is the sword used by Izanagi to kill his newborn son, Kagu-Tsuchi, after his birth burned his mother, Izanami, to death. From the blood of the Totsuka no Tsurugi, eight new Shinto gods were born.