Ikomikidomoe

was the name given to an ancient Adjuchas-class Hollow that was sealed inside a Zanpakutō by Ōetsu Nimaiya.

Appearance
In his sword form, Ikomikidomoe is a pure white, almost glowing, large broadsword with black spots on it.

In his Hollow form of his second release, Ikomikidomoe is a giant, humanoid creature with a long torso and elongated arms which reach almost to the ground. His forelimbs end in large claws, while his legs are much shorter. Ikomikidomoe does not have a visible neck; instead, his head is an extension of his body. His forehead is covered in hexagonal markings, while a structure extends from his nose back across its cheeks, ending in large circles just beside the hexagonal markings. A long beard extends from beneath his small Hollow Mask.

Personality
Ikomikidomoe is quite prideful and arrogant, and is insulted when regular Shinigami even voice the possibility of being on the same level as his current wielder. Likewise, Ikomikidomoe ridicules the mere idea of an Arrancar as young as Grimmjow Jaegerjaquez wanting to be the ruler of Hueco Mundo. Despite this, Ikomikidomoe does have respect for Baraggan Louisenbairn to some degree, and was mournful when he heard the other Hollow had perished.

Ikomikidomoe also appears to have misogynistic beliefs, as he instantly assumed Tier Harribel and Nelliel Tu Odelschwanck were mere "mistresses" of Baraggan, rather than the powerful rulers they actually are. He is also vengeful in nature, as he swore revenge against the Royal Guard for defeating him millennia prior.

Despite being turned into a Zanpakutō, Ikomikidomoe has no true loyalty towards his wielder, and is only forced into obedience by their immense Reiatsu. The moment Hikone Ubuginu's Reiatsu was lowered to a level beneath Ikomikidomoe, the Zanpakutō tried to devour them.

History
In the primeval days of Soul Society, the Hollow that would become Ikomikidomoe was an exceptionally powerful Adjuchas Hollow. Due to this Hollow's potential and power, he was respected by even Baraggan Louisenbairn, and the two made a pact to never interfere with each other.

At some point in the past, before the Shinigami had access to Zanpakutō, this Hollow attacked Soul Society and even defeated a young Genryūsai Shigekuni Yamamoto before attempting to devour the Soul King himself. However, the Hollow was defeated by Ichibē Hyōsube, who used Ichimonji to erase the Hollow's name. Since the Hollow contained too many consumed Souls to purify at once, Ōetsu Nimaiya sealed the Hollow inside a Zanpakutō, and Ichibē used Shirafude Ichimonji to rename the Hollow as Ikomikidomoe. It was hidden away by Nimaiya in the Hōōden until the Wandenreich invasion of Soul Society, when Tokinada Tsunayashiro stole the sword during the chaos.

Powers & Abilities
Infinite Evolution: Similar, though not identical, to the ability of Aaroniero Arruruerie, Ikomikidomoe has the potential of limitless evolution through consuming the power of other beings; namely by endlessly accumulating the full Reiatsu of any of his countless victims. Even though Ikomikidomoe remained an Adjuchas his power continued to grow to such an extent that even Baraggan Louisenbairn, one of the first Vasto Lorde, acknowledged Ikomikidomoe's strength, and called him a "willful calamity". Upon assimilating a few Soul King fragments that composed Hikone's being, Ikomikidomoe gained the ability to break free from the curse Ichimonji placed upon his name.

Immeasurable Spiritual Power: Ikomikidomoe is repeatedly noted to have colossal amounts of Reiryoku that surpasses even Arrancar born from Vasto Lorde. His levels of Reiryoku impressed Baraggan Louisenbairn, a very powerful Hollow in his own right, and is outright described as an "inexhaustible supply". Likewise, this level of power allowed Ikomikidomoe to even defeat a younger Genryūsai Shigekuni Yamamoto, albeit before the Shinigami had access to his Zanpakutō. However, Ikomikidomoe's power is seemingly still inferior to that of Kenpachi Zaraki, who defeated the powerful Hollow with a single blindsided strike from his Shikai. The Reiatsu of Ikomikidomoe is said to trigger a primal fear in Shinigami and Quincy.

Purificaton resistance: Due to the sheer amounts of Souls he assimilated over his lifetime, Ikomikidomoe could not be easily purified by a Zanpakutō like a conventional Hollow. Indeed, even after being crushed by the full might of Kenpachi Zaraki's Nozarashi, Ikomikidomoe was noted to still be alive, albeit weakened and unconscious. Because of this, and the fact that outright erasing Ikomikidomoe's existence like Quincy do would be disastrous for the Balance of Souls, Ichibē Hyōsube chose to have Ōetsu Nimaiya seal Ikomikidomoe inside a Zanpakutō instead.


 * Like all Hollows, Ikomikidomoe can freely open Garganta portals to travel through. Even as a Zanpakutō, he can do this either on command, or on his own violition, such as when he feels his wielder's life is in danger.

Sonído Master: Despite Ikomikidomoe's bulk, he has demonstrated incredible speed in battle, allowing him to easily perform powerful hit-and-run strikes on other fast opponents such as Grimmjow Jaegerjaquez or Tier Harribel.

Cero: Ikomikidomoe can fire powerful Cero from his single eye.

High-Speed Regeneration: By absorbing Reishi from his surroundings, Ikomikidomoe can rapidly regenerate almost any injury.

Release Forms
Due to its unique nature, being a Zanpakutō forged from a Hollow, Ikomikidomoe has numerous release commands that each draw out certain amounts of his power. Resembling Shikai commands, each subsequent release draws out more of Ikomikidomoe's true power.


 * The first release command; the blade of Ikomikidomoe transforms into a massive Hollow arm that can attack foes on its own initiative.


 * The second release command; Ikomikidomoe transforms into a gargantuan Hollow noted to be around the size of the Espada Yammy Llargo's Resurrección or the Gillian spouting Hooleer.


 * Enhanced Roar: In this form, the mere roars of Ikomikidomoe can shake and devastate a part of the Rukongai.


 * Hollow Spawning: In this form, Ikomikidomoe can spawn numerous and varying Hollows to overwhelm opponents. These Hollows are said to resemble Adjuchas in both appearance and power.


 * The third release command; Ikomikidomoe transforms into a large, humanoid Hollow; though smaller than his previous release it is still the size of a house. While this form resembles an Adjuchas, its power is greater than an Arrancar born from a Vasto Lorde.
 * Reiatsu Blast: In this form, Ikomikidomoe can release a massive blast of Reiatsu, strong enough to injure three Espada even after the attack was blocked.


 * Said to be the true, full name Ichibē Hyōsube granted Ikomikidomoe with. This form, which Hikone compares to a Bankai or Resurrección, allows Ikomikidomoe to fuse with his wielder and draw out both their maximum potentials. When used by Hikone, the blade of Ikomikidomoe remains the same, while Hikone's own appearance starts to resemble that of a Hollow. The sclera of Hikone's eyes turn black, while a third eye resembling one of Ikomikidomoe's Hollow form spouts on their forehead. A black striped pattern is now present on Hikone's face while black hexagonal markings appear on their shoulders and their fingernails turn into sharp talons. Hikone's Shihakushō turns white while black Reiatsu pours over their arms and legs. Ikomikidomoe's Hollow mask and beard are also visible on Hikone's lower back.

Weaknesses
Conditional Wielding: Due to being a special, inherited Zanpakutō, Ikomikidomoe can only be wielded by select individuals. Specifically, only powerful hybrids such as Ichigo Kurosaki or Hikone Ubuginu can use Ikomikidomoe's power. If any regular Shinigami were to attempt to use Ikomikidomoe, they would be killed by the ensuing "Soul Suicide".

Name Curse: After having his original name erased by Ichibē Hyōsube's Zanpakutō, Ichimonji, Ikomikidomoe's power was significantly weakened, and he was rendered unable to speak its original name aloud anymore. Likewise, after being renamed by Shirafude Ichimonji Ikomikidomoe was bound into servitude by whoever held his blade.

Appearances in Other Media
Ikomikidomoe appears in Bleach: Brave Souls during Hikone’s ultimate attack; Hikone uses Ikomikidomoe’s second release and summons his giant Hollow form, releasing a large burst of energy that creates several tornadoes.

Trivia

 * The name "Ikomikidomoe" is not actually an existing word, but rather a combination of Kanji. refers to things that are "similar" or "the same", while  refers to the shape of a comma symbol.