Hollowfication

Hollowfication (虚(ホロウ)化, Horouka) is the term used to describe when a Shinigami gains Hollow powers. The result is a Hollow-Shinigami Hybrid or a Vizard. The term is also synonymous with the act of donning a Hollow mask.

Creation Process
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 Hollowfication exists when the barrier separating Shinigami and Hollow is brought down.

Process 1
(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-Shingami Hybrid or Vizard is an extremely rare occurrence of this process.

When Ichigo'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 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 a high level of spiritual energy is a factor in this outcome.

Process 2
(Unknown Infection): It is unclear how the other Vizard 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 spiritual energy as compared to souls with low-level spiritual energy, causing those infected great sickness and fatigue, until they vomit up 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.

Process 3
(Hōgyoku): The Hōgyoku possesses the ability to transform a Shinigami into a perfect Hollow-Shinigami Hybrid.

Urahara's Hōgyoku played a vital part in the process of making the Vizard 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, though they didn't become complete Hollows due to his intervention and did eventually gain control over their new power.

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 Vizard had to deal with at one point or another in order to master their abilities.

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 Vizard 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 his true sealed away Hollow powers. The circumstances behind this are yet to be explored in detail to determine if this is a unique situation or just something we have not yet seen amongst the Vizard.

Attained Abilities
Hollow Masks: After a Shinigami obtains Hollow powers, they must don their Hollow mask in order to access them. The mask eventually crumbles and disappears after a certain period of time, which varies for each Vizard. For example, on her first try, Mashiro Kuna could maintain her mask for at least 15 hours without tiring. On the other hand, Ichigo could only maintain his mask for four seconds at first, though he managed to train enough with the Vizard to maintain it for a confirmed 11 seconds prior to his second battle with Grimmjow Jaegerjaquez. This is the reason they go under special training to build up their stamina so they could hold their masks for a longer period of time. The appearance of each Hollow mask is different to the individual.


 * Power Augmentation: Due to the effects of Hollowfication, the Shinigami's strength greatly increases as well as their agility, speed, stamina and pain tolerance.


 * Hollow Powers: In addition, the Shinigami may also obtain access to Hollow powers such as Cero and High-Speed Regeneration, Telekinesis, Sonído.

Those who have undergone Hollowfication

 * Vizard: The most well-known group of Shinigami who have undergone Hollowfication are the Vizard. There are eight members of the Vizard, 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.


 * Kaname Tōsen: Former Captain of the 9th Division. Turned traitor with Sōsuke Aizen and given Hollowfication for his loyalty.

Appearance in Other Media
In Bleach: Fade to Black, the characters of Homura and Shizuku underwent a different form of Hollowfication, absorbing a Hollow into themselves, and later merged with Rukia Kuchiki to create the hybrid being known as Dark Rukia. A similar form of Hollowfication occurs in Muramasa during the Zanpakutō Unknown Tales arc, as a result of absorbing Hollows to sustain his existence. Both of these forms involved pre-existing Hollows being merged with the individual in question and then forced into submission, rather than a completely new Hollow being spawned from their consciousness.