Kidō spells are used by Bleach characters of the shinigami race for various purposes. Spells exist for attacking, binding, and healing. Like conventional magic, most of these spells require an incantation of some sort to activate their effect. They are performed through channeling spirit energy, which the incantation then focuses into a specific effect. As stated by Ganju Shiba, the principle behind kidō and channeling spirit energy in general is a mental image of throwing oneself within a darkly-colored circle. With the exception of healing, which requires no incantation or even a name to perform, kidō spells consist of four distinct steps: reciting the incantation of the spell (which is usually long-winded), its category (binding or destructive), its number, and finally its name. The number of a spell determines the difficultly of casting it correctly and effectively (#1 is simple to cast, #99 is incredibly difficult). With sufficient training, the first step can be bypassed, allowing spells to be used in combat quickly. Doing so, however, lessens the spell's effect, the degree of which is dependent upon the skill of the caster. Bypassing the incantation is also more difficult for higher-numbered spells, as casting them is already fairly difficult even with the full verbal component. The power of kidō spells varies on the skill of the user; even a low-level kidō spell can be utterly devastating when utilized by a sufficiently powerful user. Complementing kidō may be combined for a single ability, something that Isane Kotetsu demonstrated when she used binding spell #58 to locate Sōsuke Aizen and Gin Ichimaru within Soul Society, and then #77 to convey the information to every captain and lieutenant (as well as Ichigo Kurosaki and his friends). Rukia Kuchiki has also demonstrated the ability to use two kidō spells simultaneously by alternating between the lines of each incantation. Kidō can also be combined with other forms of shinigami combat to form unique abilities, such as Yoruichi Shihouin's flash cry ( shunkō lit. instant war cry) technique, which combines kidō energy and hand-to-hand combat (hakuda) to concentrate spiritual power at the back and shoulders for quicker movement and increased attack power.
