Reishi Core

"Ladies and Gentleman, I bring you. The Reishi Core, the latest in Shinigami Technology."

- Nobu Sadao

s (霊子 ちゅうしん, Spiritual Particle Core), alternatively referred to as a Reishi Heart and a Reishi Storage Container, was an efficient energy capacitor designed and manufactured by the Shinigami Research and Development Institute. The exact purpose of the Reishi Core was to aide in the storage, retention, powering and the equal distribution of reishi into various machines, weaponry, and devices.

Design and Characteristics
A Reishi Core was an easy to manufacture particle capacitor, scaled for installation on various degrees of devices such as machinery, equipment, and weaponry. Even were also given the capability to utilize them, albeit temporarily. The Cores was designed to retain excess Reishi found in the environment of and be used as an alternative power source to fuel the demanding functions delegated by numerous devices. This occurred through an undisclosed process, where reishi was forcibly transmuted into reiryoku for easy use. Easily mass produced and inexpensive, the Reishi Core could readily replace the need of a Shinigami's own Reiryoku in exchange for a limited operation time. The Reishi Core appeared in a form quite similar to that of the Quincy's Gintō - cylindrical chamber capsules that were almost the size of the wielder's hand. The Reishi Core was built with a super conductive metal, allowing it to store and react to reishi and reiryoku.

When used for various machines, weaponry, and devices, the color of the Reishi Core was a default blue. When personally used by the Shinigami, the color of the Core could change in accordance to their own reiryoku type or their personal preference. When active, the Cores possessed a vibrant hue of its associated color. But when it's completely devoid of reishi and reiryoku, the Core would take on a slate gray appearance.

The various colors the Reishi Core became were designed to act as a form of indicator for its status:
 * Blue: Default Color. Meant to indicate Full Power Status.
 * Yellow: Warning Color. Meant to indicate Half Power Status. When nearing the Gray Color, it would start to blink. Could also used as a Personal Preference Color.
 * Red: Meant to indicate an Overdrive State, allowing the Core to expel all of its contained reishi/reiryoku for a brief yet drastic increase in power. Could also be used as a Personal Preference Color.
 * Gray: Completely devoid of Reiryoku and Reishi. Meant to indicate Inactive Status.

Development History
The Reishi Core's most prominent use was with the automated weapons known as the Kikai Mitsukai, where it routinely acted as the main power

Weaknesses
Reishi Cores were not infinite, and thus suffered from an inferior operation time and required routine replacement. While Reishi Cores had enough energy to stay functioning for about 3-4 hours, that number would often be drastically shortened due to constant use of said energy. However, this weakness was often mitigated through the inclusion of additional Reishi Cores.

Reishi Cores also possessed an inherent design flaw: fragility. The Cores had no form of kinetic protection and could be easily crushed if the outer protective layer was broken.

Notable Uses

 * Various Kidō Spells
 * Kikai Mitsukai
 * Reishi Gun
 * Kidō Gun

Trivia

 * Due to a strange fascination with the colors of the Reishi Core, many of the started to collect the Cores simply for the sake of gathering all the colors together.
 * Reishi Cores were commonly used by the Vice-Captains and the Seated Officers of the Gotei 13. The only Captains known to use the Cores were Yuuna Tomoko, Nobu Sadao, and Kei Yume, each for their own respective purposes.
 * Yuuna Tomoko used the Reishi Cores as an alternative means to access her Adult Form, without having the need to activate her Shikai.
 * Nobu Sadao used the Reishi Cores to power his various inventions, especially his Body Modifications that required an excess amount of reiryoku.
 * Kei Yume used the Reishi Cores to power the Kikai Mitsukai that silently guard the Yume Family Manor.

Behind the Scenes

 * were partially inspired by the GN Condenser, particle capacitors used to store excess energy found in the Gundam Meta-series, Mobile Suit Gundam 00.
 * The appearance of the was based on the Cores, devices used to create and summon the titular Monsuno of the Japanese-American Television Series, Monsuno.
 * The Concept of the was created due to a need to explain how the Kikai Mitsukai was able to function without an outside stimulus.