Reishi

, sometimes also called Spiritrons, are the fundamental particles which make up all spiritual things. This includes the spiritual bodies of the Hollows and Shinigami, and the two planes of existence, Hueco Mundo and the Soul Society in their entirety. Reishi are invisible to mortals (such as Humans with the exception of spiritually aware ones such as the Quincies); they can, however, still interact with normal matter and produce physical effects. It is noted, however, that Spiritrons and atoms do not mix well.

There is a certain amount of Reishi in the Human World, too. More free Reishi tend to be found in places closer to nature. Quincy collect these Reishi to use for combat in the form of Reiryoku.

Reishi in the atmosphere is also able to be controlled freely, allowing a person to gather it under their feet so that they can stand in air. Reishi is the basis for the following techniques:

Hirenkyaku: The method in which Quincy use to travel quickly over short distances. It is basically the Quincy equivalent to the Shinigami's Shunpo, or the Arrancar's Sonído. .


 * Platform Manifestation: An instance of Hirenkyaku, that allows the user to create a platform of reishi under their feet. It can be used in the Garganta, and Hueco Mundo.

Shunpo: Flash Steps; The method in which shinigami use to travel faster than the eye can follow. .

Quincy: Letzt Stil: The Quincy gains a vast increase in power, absorbing all the reishi from their surroundings into their attacks. It actually deconstructs objects made up of reishi.