Susanoo Weapon

This is a simple chakra blade that the user's Susanoo is capable of creating and wielding. Just like the Susanoo itself, each particular blade is unique to the individual involved. Sasuke Uchiha's resembles a regular blade and is wielded by the primary left arm of his Susanoo. However, Madara Uchiha's version possesses two distinct swords that are instead wielded by the right arm of each side of his Susanoo and feature undulating blades, which resemble a kris. Itachi Uchiha's resembles a curved dagger.

Despite their diverse appearances, each sword is extremely effective, due in part to the considerable strength of the Susanoo that wield them. Sasuke was able to use his to cut through several stone pillars in a single swing, whilst Madara's could break through the combined defence of Gaara's Shield of Sand and Ōnoki's Rock Golem, which together were capable of resisting even his Yasaka Magatama attack, and Itachi's could cut through Kimimaro's bones, which were stated to be harder than tempered steel and could block a chakra-enhanced blade.

When Madara's Susanoo was used in its final form, the undulating blades become straight katana swords which are kept inside the palms of Susanoo's back arms and wielded by its forearms. In this form, one swing of the sword is enough to destroy an entire mountain range, leaving a massive trail of destruction.

Trivia

 * After acquiring his Eternal Mangekyō Sharingan, Sasuke's Susanoo was able to wield a blade composed from the black flames of Amaterasu, which ignited anything that it pierced. However, it is unknown as to whether this blade is a sword or simply an arrow for his bow.