Hollowfication (虚(ホロウ)化, Horōka) is the term used to describe the process in which (I) A Plus shifts into a Hollow. (II) To increase the strength limit of a Konpaku by removing the boundary between Shinigami and Hollow's. This allows one to gain tremendous power if one's inner-Hollow can be controlled. A Hollow-like mask appears when entering this state. The result is a Hollow-Shinigami Hybrid or rather a Visored. The term is also synonymous with the act of donning a Hollow mask.
By gaining the strength of a Hollow, one's Reiryoku increases dramatically. Only those who have control over their Inner-Hollow can Hollowfy. It manifests itself as a unique mask of different shapes and designs.
When Ichigo's Hollow powers started to increasingly manifest while not under his control, Shinji explains that Ichigo's conflict with his inner Hollow is a common symptom other Visored had to deal with at one point or another in order to master their abilities.
The process by which to activate such a transformation has been shown to be achieved by three possible methods, though only two are known in any real detail. In any process, the main determination of having achieved Hollowfication is the manifestation of a Hollow mask.
Shattered Shaft Training: This process is based entirely on force of will by a normal soul, though with the intention of gaining Shinigami powers, it doesn't have access to or failing and becoming a Hollow. Becoming a Hollow-Shinigami Hybrid or Visored is an extremely rare occurrence of this process.
EX: When Ichigo Kurosaki's spirit chain was completely eroded, he underwent the normal transformation of a Plus into a Hollow. The significant difference is that normally, when a Plus transforms into a Hollow, the spirit form shatters and reconstitutes itself into the new, monstrous form. Ichigo's transformation was entirely out of sequence, as the Hollow mask was being formed first while his body was still that of a Plus (showing that he was resisting the transformation). Ichigo Kurosaki enters into an internal world where he is forced to find his spiritual powers in a small amount of time, this takes place at the exact moment of the final stages of Encroachment. Therefore, it is that singular moment that allowed Ichigo to gain both Shinigami powers and acquire Hollow powers at the same time. It is believed that having such a high level of Reiryoku is a factor in this outcome.
Unknown Infection: It is unclear how the other Visored gained their current status. What is known is that Sōsuke Aizen was instrumental in the Hollowfication process (though whether he knew of the full potential of the results is left to be questioned). This process used seems to spread as some form of possible infection through wounds, that has the desired effects on souls with high-level Reiryoku as compared to souls with low-level Reiryoku, causing those infected great sickness and fatigue, until they vomit up Reishi in the form of a white liquid that forms the beginnings of their Hollow mask, which then proceeds to transform their bodies and warp their minds. Other than that, all that is known is that the process is accelerated by aggressive emotions. The conclusive result makes a Shinigami into a primarily Hollow-like humanoid, which is a highly unstable transformation causing mindlessness and aggression.
Hōgyoku: The Hōgyoku possesses the ability to transform a Shinigami into a perfect Hollow-Shinigami Hybrid.
Kisuke Urahara's Hōgyoku played a vital part in the process of making the Visored currently what they are, as he tried to use it to return them to their previous Shinigami state. But according to Urahara, what his device did was not what he had intended (turning them into a stable form of complete hybrids) and he considers the solution a failure on his part. However, they didn't become complete Hollows due to his intervention and did eventually gain control over their new power.
The Hōgyoku is insinuated to have had a hand in turning Kaname Tōsen into a perfect Hollow-Shinigami Hybrid. While maintaining all the added benefits of a Visored transformation, Tōsen is notably different in the regard that to date he not only possessed a Hollow Mask but a Resurrección allowing him full access to a true sealed away complete Hollow Form. The circumstances behind this are yet to be explored in detail to determine if this is a unique situation or just something not yet seen amongst the Visored.
Those who have undergone HollowficationEdit
- Visored: The most well-known group of Shinigami who have undergone Hollowfication are the Visored. There are eight members of the Visored, whom were all either former Gotei 13 captains or lieutenants (including Hachigen Ushōda, who was Kidō lieutenant of the Kidō Corps, and Substitute Shinigami Ichigo Kurosaki). As Aizen stated, "a normal soul can't contain the prototype" when undergoing Hollowfication, therefore Shinigami of a high spiritual level have to be the ones who undergo this process.