Zanpakuto
Kenpachi does not know the name of his Zanpakutō, and is the only captain of the Gotei 13 who cannot perform bankai.
* Shikai: Despite not knowing its name his Zanpakutō is constantly released in some form of released state due to his immense Spiritual Pressure (much like Ichigo's Zangetsu). In other words his zanpakuto is constantly in a shikai state without having the additional abilities a shikai may grant it's user. The sword's appearance is a reflection of Kenpachi's own practice of weakening himself to fight: it is a seemingly worn-down and dull blade with a guard that extends inward from its center. The blade is much longer than that of a standard Zanpakutō. Despite its appearance, it is easily capable of cutting through most objects. This is demonstrated when he stabs straight through Ichigo's Zanpakutō and later slices a building in half with careless effort after releasing the full force of his spiritual power