Zanpakutō

A Zanpakutō (斬魄刀; literally, soul-cutter sword) is the main weapon of the Shinigami, the Arrancar and the Visored. The art of wielding a Zanpakutō is called Zanjutsu (斬術; literally, swordsmanship).

Overview
Zanpakutō are the trademark weapons of the Shinigami. Capable of cutting spiritual bodies, they are amongst the few weapons which can be used to combat Hollows. Each Shinigami carries a Zanpakutō, and each Zanpakutō is unique: as the swords are both reflections of a Shinigami's soul and power, and sentient beings unto themselves. The Zanpakutō's name is also the name of the living spirit that empowers the sword and lends its strength to the Shinigami who wields it. These beings can vary greatly in appearance and have their own distinct personalities which match their owner's. Normally, the Zanpakutō spirit can only be seen by its wielder. Otherwise, they dwell in their own "inner world", created within the minds of the Shinigami who wield them. As such, each Shinigami's inner world is drastically different from another Shinigami's and is unique to themselves. A Zanpakutō's spirit can bring its wielder into its inner world, though Shinigami can voluntarily achieve this simply by meditation.

A Zanpakutō's shape and abilities are based on their Shinigami's soul. Once a Shinigami learns his/her sword's name, they are able to communicate with one another and grow stronger together. Zanpakutō are born with their Shinigami and they die along with their Shinigami. Shinigami use them in battle as a reflection of their heart. When released, they can display a vibrant power. They are one with the Shinigami, and they share a Shinigami's conviction.

Asauchi (浅打ち; literally, "shallow hit"): The class of nameless Zanpakutō that all low-class Shinigami wield. Shinigami who are still in training - those who do not yet belong to any of the Gotei 13 - all wield generic Zanpakutō. Shinigami who are unable to communicate with their Zanpakutō, the "shallow hit", which refers to the grossly-reduced power of a Zanpakutō whose wielder cannot connect with it properly.

Zanpakutō Facts

 * Because they are part of their owner's soul, a Zanpakutō cannot be replaced, though it will slowly regenerate if it is broken.
 * The Zanpakutō size reflects the amount of the swordsman's spiritual power, although a Shinigami will be able to control that size by controlling Reiatsu output.
 * If a Shinigami pierces the chest of a human with their Zanpakutō and channels their Reiryoku through it into the Human's body, it will transform that human into a Shinigami temporarily. The act does not have a high chance of viability even when the human in question has a high level of spiritual energy, and if the method does fail the human will die.
 * Every Zanpakutō has its own name.
 * A Zanpakutō can determine whether or not its wielder is worthy of its power.
 * Normally, even a broken Zanpakutō would return to its original state as its wielder recovered.
 * Zanpakutō have a true form. This true form resides inside their Shinigami. A Zanpakutō has a mind, and a body that controls their powers. Shinigami are able to grow more powerful by communicating with them.
 * Zanpakutō possess their own reiatsu, which can be sensed as any reiatsu can and is identical to that of their wielder though with subtle differences.
 * Though rare, it is not impossible for more than one soul to be attuned to the same spirit. In such cases, ancient law of the Soul Society will not allow two beings to wield the same Zanpakutō, in which case, they must duel for ownership of the spirit, with the winner gaining it and the loser being sentenced to death.
 * No matter what form (or size) a Zanpakutō takes, it is always virtually effortless for its owner to wield because it is a part of its owner's soul. Shinigami captains all consciously keep their Zanpakutō in a manageable size, otherwise they would be holding Zanpakutō the size of skyscrapers. Therefore, one cannot judge one's opponent's strength solely by the size of their Zanpakutō.

Sealed
Normally as Katana's, Nodachi's, or Wakizashi's, but sometime's seen in other forms.

Shikai
Represents both the Zanpakuto and the wielder's soul, this is the Zanpakuto's true form.

Bankai
By training for ten years, a Shinigami will be able to unlock a second form, where the Zanpakuto's power is put to the max.

Types
There are several types of Zanpakutō though only three types mentioned (Melee, Kidō and Elemental). Kidō has many sub-groups and the Elemental-types while part of Kidō-type grouping, is so big and diverse that is able to stand on its own as its on grouping. (Note, Types are determined by what a Zanpakutō is shown and/or stated to be capable of within the confines of these types and nothing more). These types include:

Kidō-Subtypes
Certain Zanpakutō possess defined abilities (ex. Poison, Projectile) and exist in their own category. Due to them being designed around a special ability they are therefore a form of Kidō-Type Zanpakutō.

Elemental-Subtypes
A large amount of the Zanpakutō are classified by elements, generally utilizing their respective elements as forms of attack. Elemental Zanpakutō are all Kidō-sub-type which have an element.

General Subtypes
There are a few "sub-types" of Zanpakutō classification such as:
 * Constant-Release Type: Zanpakutō that are always in Shikai form because of the strength of their wielder's spiritual energy, or, more importantly, their lack of control over it. (80 years ago)
 * Mikio Yoshimura (80 years ago)
 * Aira
 * Dual-Blade Type: Zanpakutō that feature more than one blade in Shikai release. It is decidedly rare for one to possess such a weapon and therefore it says a lot about the uniqueness of its wielder's spiritual power.
 * Mouri Tsurijo
 * Sanosuke Kyoya
 * Inazuma Kazuo