Kidō (鬼道, "demon way", or "spirit way" sometimes translated as Demon Arts; Viz "Soul Reaper's powers"; "Spells") is the technique that Soul Reapers use to focus their Spiritual Pressure into a wide variety of what could be considered magic spells. According to Sōsuke Aizen, it is one of the four basic Shinigami combat forms.
The Kidō Corps is a branch of Soul Society's military which excels in the mastery of Kidō.
Each spell is graded on a scale from 1 to 99, with a direct corelation to how powerful and difficult to perform the spell is. It is unknown if multiple spells can share the same level, the only examples coming from acanon anime scenes.
Ordinarily, practitioners of Kido must speak a lengthy incantation in order to use the spell. However, many who fight with Kido use Eishōhaki (詠唱破棄, lit. "Incantation Abandonment"), a technique that releases Kidō without a spirit chant. While it does speed up the process, it can dramatically weaken the spell.
It is also possible to use Kōjutsu Eishō (後述詠唱, lit. "Later Mention Incantation"), or a recitation of the incantation made after initiating the spell in order to increase its power. So far, only Hachigen Ushōda has been seen using this technique.
The power of Kido is dependant on the power of the user, as even a low-level spell can be utterly devastating when used by a Captain class Soul Reaper.
Kidō can also be used for practical purposes. Renji Abarai demonstrated that he could manipulate a Hado spell to serve as a makeshift torch, even though he's considered to be a very poor Kido-user.
There are three main types of Kidō: binding spells, destruction spells, and healing spells.
- Bakudō (縛道, lit. "Way of Binding"): This category focuses on spells that create barriers or immobilize or imprison targets.
- Hadō (破道, lit. "Way of Destruction"): This category contains spells that are meant to destroy or directly damage a target. As such, they are often some form of directed explosion or energy.
- Healing spells: These have never been given a specific category, specific names, or specific numbers. Usually, a user holds his/her hands above the patient's wounds and his/her palms glow with green spiritual energy to facilitate healing. According to Unohana, healing kido works by replenishing the patient's Reiatsu first, so that the body's Reiatsu can work with the healer's in order to speed up recovery.
As mentioned previously, it is not uncommong for skilled Kidō users to use various techniques to make casting more efficient or confuse enemies. Eishōhaki, Kōjutsu Eishō and Nijū Eishō (二重詠唱, lit. "Double Incantation") involves mixing the incantations of two or more Kidō spells together.