Hogyoku is a small sphere emitting a bluish glow, which in essence is a materialized clot of enormous spiritual energy and will. Initially, there were two independent prototypes, created by Kisuke Urahara and Sosuke Aizen. Both scientists, independently of each other, came to the conclusion about the need to overcome the fundamental limits of the powers of shinigami and hollows. Their research was focused on the process of turning shinigami into hollows and hollows into shinigami.
Having discovered that their unfinished creations were unstable and unable to fully realize what was intended, Aizen, having obtained Urahara's sphere, fed it to his own. As a result of the fusion of two incomplete prototypes, a single, completed Hogyoku emerged. A key feature of the artifact is the presence of its own, albeit primitive, will. It does not simply fulfill wishes, but "reads" the hearts of those around it and chooses whose aspiration for evolution is the strongest and most suitable for realization. If a being possesses sufficient potential, the Hogyoku directs its development, bypassing the standard stages and limitations established by nature. It acts not as a tool blindly carrying out commands, but as a catalyst that selectively responds to the thirst for power and change. After Aizen lost control, the artifact recognized him as unworthy and, in essence, rejected its master, which led to the sealing of Aizen himself.
