Kurozume

Kurozume (黒爪, Kurozume; literally meaning "Black Claw") is a male spirit that had once lived together with his younger brother in the realm of. While once a kind spirit that loved his brother very much, his death at the hands of the and the eventual darkening of his soul through fierce combat tainted his personality and left him but a twisted demon of his former self. He became contracted to the devious witch,, and went on to serve as a bloodthirsty assassin under her command. Kurozume is a minor antagonist of Bleach: Extinction.

History
Born in, the first child of two powerful wolf spirits, he and his brother lost their parents at a young age and were forced to survive on their own. Together, with the intention of finding a place they could call home, the brothers had eventually found their way through one of the various naturally occurring that led to the. But unfortunately, upon arriving in this strange new land, they soon came to discover that their strength as wolf spirits was not enough to protect them against the stationed in the town they arrived in; the task force clad in black had deemed the both of them as threats and attempted to destroy them. While Kurozume managed to survive the onslaught of the platoon with nary an injury, his brother unfortunately did not, and as such, the wolf spirit was forced to carry his brother to safety. Managing to both survive, Kurozume's brother was injured internally and became a cripple unable to even stand, let alone fight alongside his older brother. In his weakened state, he soon fell ill and it seemed as though his death was near.

Desperate to find a way to restore his brother to his former able self, Kurozume crossed paths with a woman named, a being with incredible magic abilities, and in her, the wolf spirit believed he found the means to finally help his poor brother. Of course, the witch would not so easily perform such a feat without what she deemed as proper compensation, and so began Kurozume's life as her indentured servant. Though an arcane ritual, he was contracted to Rosa to serve as her retainer, to do as she demanded. And as he managed to perform every task she asked of him with rather impressive success, time and time again, he would notice that his brother was slowly making a recovery. However, what he hadn't realized is that Rosa did not attempt to truly cure his brother of what ailed him, even though she more than likely had the means to do so. She would do whatever was needed to simply keep the young wolf spirit alive, so as to keep Kurozume believing that she was actually keeping her side of the agreement and that would mean the wolf spirit would continue to give his full effort toward completing the tasks given to him.

It was many years of repeated ordeals, forcing Kurozume to commit some of the most heinous crimes and murders of all manner of being; both mortal and spiritual. And it was through these offenses that the kind wolf spirit who cared deeply about his younger brother began to change. Though he was against his actions at first, without him ever noticing, he began to enjoy killing people. He would even begin to turn it into a game or challenge himself to kill people in specific ways, such as targeting a spot with minimal blood loss or seeing how many times he could crush a person's bones before they would pass out from the pain. And the wolf spirit's soul darkened with each heinous crime that tainted his spirit. It would not be long before this twisted and hollowed shell of the former wolf spirit brother began to see his own younger brother as a nuisance and a burden who only held him back. And soon after, Kurozume murdered his own brother in cold blood, wiping off the blood as he grinned in the moonlight at what he had done. The deal between him and Rosa had changed; he would continue to serve her so long as he was allowed to satisfy his cravings for combat.

Though it is not known exactly when, on many of his assignments, Kurozume had the opportunity to observe various forms of martial arts that he attempted to learn on his own. These sessions of training allowed him to further develop his combat skills which only made him all the more useful to Rosa as an assassin.