Kidō (鬼道, "demon way" or "spirit way"; sometimes translated as Demon Arts; Viz "Soul Reaper's powers"; "Spells") is a form of Shinigami combat based on advanced spells. These spells are produced with strong Reiryoku and fall into two categories: Hadō for direct attacks, and Bakudō for battle support. It is one of the techniques in the Zankensoki, the group of Shinigami primary combat skills. Kidō spells are triggered by an incantation. Experienced users can trigger them without an incantation, though the effectiveness of the spell will be diminished.
The Kidō Corps is a branch of Soul Society's military which excels in the mastery of Kidō.
Most spells are graded on a scale from 1 to 99, spells of the latter being the most powerful and the most difficult to perform. To use Kidō, a Shinigami must recite the specific incantation for the spell, which is often long and requires a few seconds to speak.
The power of a spell relies on the power of the user, as even a low-level spell can be utterly devastating when utilized by a high-class Shinigami.
Kidō can be used for practical purposes as well. Such as creating a torch by taking a spell and decreasing its power.
There are three main types of Kidō: binding spells, destruction spells, and healing spells.
- Bakudō: (縛道, lit. "Way of Binding"): Supplementary spells which can immobilize an enemy or have an effect besides a direct strike. They may seem subtle, but these spells can give their users a tactical advantage when used properly. These are a broad category of defensive spells which block/repel attacks or freezes enemies in place. This class of spells include Kidō Barriers & Seals.
- Barriers: Focused spiritual energy formed into a solid form of energy. This energy can take on many shapes or colors as determined by the user. Barriers are protective in nature, and can be as simple as a barrier only protecting one direction or encompassing all sides of an area. Barriers can be used for containment, and some barriers can be used offensively. Barriers can mask spiritual pressure and can make one spiritually and physically invisible. The strength of a barrier is dependent upon the power of the user. Weak barriers are easily breakable, while strong ones can last for centuries. Barriers created by noble blood are said to be unbreakable by those of lesser status. Certain barriers can be placed beforehand and activated later, while others require certain artifacts and time to activate.
- Seals: Somewhat similar to barriers, but far more powerful and require far more preparation to create. Seals can only be used by those of sufficient spiritual power being who are meant to hold the most powerful and/or dangerous artifacts or beings. Seals are usually hard to break.
- Hadō (破道, lit. "Way of Destruction"): Offensive spells which inflict direct damage to the enemy. Their effectiveness differs depending on the user. It is said the effectiveness of the higher-ranked spells are beyond imagination.
- Kaidō (回道, lit. "Turn Way"): Also known as healing Kidō (治療用鬼道, chiryōyō kidō). These spells do not have known names, numbers, or incantations to cast, and simply heal the target. As the user holds his/her hands above the patient's wounds, his/her palms glow with green spiritual energy to facilitate healing. When one heals with regular healing kidō, they perform Reiatsu restoration first. By doing so, one can attempt to recover the physical body using the patient's restored reiatsu and the healer's external reiatsu. Therefore, restoring the reiatsu when the physical body is in a fully healed state is no trouble at all.