Hōgyoku



The Hōgyoku (in Japanese: 崩玉, Crumbling Orb; Viz: "Breakdown Sphere") is a mystical item that can take down the barriers between Soul Reapers and Hollows, allowing for the creation of an Arrancar, a Hollow with Soul Reaper powers, or a Vizard, a Soul Reaper with Hollow powers. Kisuke Urahara invented this item, and Aizen stole it from Rukia, whose body Urahara had sealed the Hogyoku in. Aizen uses the Hogyoku to create an army of Arrancars in preparing to overthrow the king of the Soul Society.

Description
The Hogyoku is a small, bluish-purple cube-like orb composed of a unique substance thought to be capable of dissolving the boundaries between Shinigami and Hollows, allowing one race to attain the powers of the other. However, its true power lies in its ability to sense the hearts of those around it, and to materialize their deepest desire.

Powers and Abilities
The Hogyoku is a powerful and magnificent gem that possesses tremendous abilities and powers:
 * Overbearing Power: When Tessai Tsukabishi first witnessed the Hōgyoku, he remarked that it possessed an overbearing power unlike anything else in Soul Society, a power completely unrelated to Reiatsu. He goes on to say that its very presence felt as though it were trying to stifle his very existence with its power.
 * Desire Materialization: Though initially thought to solely possess the power to control the boundary of the two contravening existences, that of Shinigami and Hollows, this was proven incorrect. Rather, the Hōgyoku's true power is the ability to capture and materialize the hearts of everything that exists around it. However, this power is not without limitations. Not only must the target’s heart be in the vicinity of the Hōgyoku, it has to possess a very high-level of spiritual power, otherwise the desire will not be fulfilled. Aizen claims that all the events that happened around Ichigo Kurosaki, Rukia Kuchiki and Kisuke Urahara were events materialized by the Hōgyoku itself, which possesses a will of its own.


 * Hollowfication/Arrancarification: While not truly an ability of the Hōgyoku itself, the orb took on this property because it is what Kisuke Urahara desired when he invented it. Through this power, the Hōgyoku could be used to bypass the barrier that separates Shinigami and Hollows. As such, it can cause Shinigami to undergo Hollowfication, and Hollows to undergo Arrancarification. These processes lead to the creation of a Hollow-Shinigami hybrid and an Arrancar, respectively.
 * Fusion: As demonstrated by Aizen, the Hōgyoku can be embedded into one’s body, almost fusing with it completely. In this state, the Hōgyoku instinctively protects its master by healing its master’s injuries almost instantly, in a manner similar to a Hollow’s high-speed regeneration. As the Hōgyoku’s will further understands its master’s heart, the fusion between them progresses, restructuring his soul and triggering a transformation.