Hikone Ubuginu

Hikone appears as a small, androgynous child of striking beauty, with dark skin, short dark hair, and vivid red eyes. Their usual attire is a shoulderless red shihakushō worn without footwear. A lengthy chain fixes their sword against their back.

Polite, upbeat, and quick to fret whenever they fear they have caused offense, Hikone behaves with the earnest sweetness of a young child. Their obedience to Tokinada Tsunayashiro and their creator Aura Michibane is total, and they carry out orders with a flat, mechanical eagerness. Because they were made rather than born, Hikone regards Tokinada as a father figure and Aura as a mother, treasuring any chance to prove useful and sinking into near-suicidal despair whenever they believe they have let Tokinada down.

That gentleness vanishes on the battlefield. Hikone cuts down anyone standing between them and Tokinada's aims without hesitation, even people they have come to like, such as Shūhei Hisagi. Facing Kenpachi Zaraki, they discover an unexpected thrill in fighting a powerful rival, and observers note that their temperament starts to echo Gremmy Thoumeaux, the Quincy whose brain forms their core.

Before the Wandenreich assault on Soul Society, Tokinada Tsunayashiro commissions Seinosuke Yamada and Aura Michibane to build an artificial hybrid Soul. Despite blending thousands of spirit fragments taken from Quincy, Fullbringers, Humans, Soul Reapers, and even the Soul King himself, the result barely clings to life until Tokinada supplies the brain of the slain Quincy Gremmy Thoumeaux as a stabilizing core, finally completing Hikone.

Presented to the world as the coming Soul King, Hikone is dispatched to Hueco Mundo and later the Rukongai to subdue Arrancar, Quincy, and Fullbringers by force. They wield a one-of-a-kind sword, Ikomikidomoe, forged from a primordial Hollow and able to speak aloud, which unfolds into a gigantic Hollow when released. Drawing on their mixed heritage, Hikone fires Cero and Gran Rey Cero, hardens their body with Hierro, layers on the Quincy Blut and Hirenkyaku, and blends multiple races' high-speed movement into a single blur.

Their power crests when they invoke the blade's full name and take on a Hollow-like Resurrección, their reiatsu surging to levels compared with Aizen after the Hōgyoku. During the climactic clash they trade blows with Zaraki, though the sword eventually devours the Soul King fragments within them and, once wrecked, leaves Hikone reduced to barely more than an ordinary recruit.