Hollow

Biodata

Classification and Evolution

Hollows can gain power and evolve by devouring their own kind. Their individual abilities and strength vary even within the same rank 39 67 212.

Not every evolution follows the usual pattern. During a war in Hueco Mundo, increased atmospheric Reishi caused some Giant Hollows to become mindless Gillians simply by breathing 88. Arrancar can still gain Reiatsu by eating, but the growth is much less pronounced than before their transformation 140.

Origins and Nature

Human souls can fall and become Hollows when attachments or other circumstances prevent them from ascending. Animals can also become Hollows: resentment after death is described as one cause 21 38.

Many weaker Hollows hunt souls with little or no reason, but intelligence varies. Yanis, an Adjuchas, possessed humanlike intelligence and hunted selectively; other Hollows formed factions and conducted scientific research 3 18 104.

Appearance

Hollows take widely varying forms, including humanoid, insectlike, and animal-shaped bodies 3 8 9.

• Masks: Hollows encountered by Rei had hard masks; breaking them killed several weaker Hollows 8.
• Holes: A Hollow may have a conspicuous hole in its body, such as the chest hole of the first Hollow Rei encountered 3 21.
• Size: Giant Hollows can exceed ten meters, while Rei encountered a powerful Vasto Lorde with a more humanlike build 12 21.
• Arrancar features: Mask remnants and Hollow holes can remain after transformation, as seen with Picaro and Grimmjow 134 241.

Abilities and Weaknesses

Devouring

Hollows consume souls and other Hollows. Devouring their own kind can fuel evolution, while their masks contain much of their power 9 23 39.

• Yanis stated that eating an entire Hollow yields all the power it had in life. Draining one instead can cause its spiritual body to collapse before all its power is taken 23.
• According to Yanis, the mask contains the core of power in 90% of Hollows and accounts for at least 80% of their power 23.

Individual abilities

Hollow abilities vary by individual and are not universal 15 21 23.

• Regeneration: A one-legged Hollow healed a neck wound, but five Ragged Hollows Rei later captured lacked High-Speed Regeneration 8 23.
• Cero and Bala: Gillians and stronger Hollows use Cero; an Adjuchas also used Bala against Rei 38 86.
• Specialized attacks: A spider Hollow used webbing and venom capable of melting a human body 15.
• Body Possession: Yanis injected Reishi carrying his consciousness into targets to erase their consciousness and alter their bodies’ Reishi structure 21.

Masks and purification

Rei found that breaking a weaker Hollow’s hard mask caused it to dissolve into Reishi. One such Hollow had survived and regenerated from a wound elsewhere on its body 8.

Soul Reapers can purify Hollows with their Zanpakuto; purified Reishi was shown traveling to the World of the Living and becoming the souls of unborn children 111. Quincy historically eradicated Hollows entirely, contributing to an imbalance of souls. Rei later devised a way for Quincy to purify rather than destroy them 74 259.

Hollowfication

Hollowfication introduces Hollow power into another being. It can greatly increase combat strength, but an invading Hollow may struggle with its host for control, and an unsuitable subject’s soul can collapse 37 109 111.

• Rei and Yanis: Yanis attempted to possess Rei, who suppressed him with Kurenai’s help. Their later cooperation allowed Rei to use Hollow power and devour masks 20 21 23.
• Seigen Kyōshiba: Aizen caused Seigen’s Hollowfication. Hollow scientists later suppressed the Hollow power with Soul Reaper power, leaving Seigen able to use it in battle 111 121.
• Artificial Hollows: Tōsen’s researchers cultivated Hollows for fusion. Their experimental “Growth-type” Hollows retained a devouring ability, but evolution risked allowing another consciousness to replace the host’s 212 213.
• Quincy risk: Ryūsaki refused fusion because Hollowfication could damage his Quincy abilities and might prove fatal 212 213.

Hueco Mundo

Hueco Mundo is a world parallel to Soul Society and the World of the Living. Before Rei’s reforms, it was a desolate expanse of desert, rocky mountains, and Quartz Trees; its underground Menos Grande Forest housed Gillians, Adjuchas, and other Hollows 38 88 212.

Hollows hunted one another there, while stronger factions fought for territory and followers. Grimmjow’s Blood Panther Group battled Baraggan’s Las Noches, using Gillian ranks to exchange Cero volleys 60 94. Later, Grimmjow, Ulquiorra, Nel, and Tier Harribel established the Hueco Mundo Council to resist outside invasion 212.

After becoming the new Soul King, Rei created a sun, ocean, vegetation, and five safe cities in Hueco Mundo. He assigned Yanis, Ulquiorra, Nel, Harribel, and Grimmjow responsibility for maintaining order there 259.