Koga Kuchiki

Kōga Kuchiki (朽木 響河, Kuchiki Koga) is a Shinigami introduced in the anime-exclusive Zanpakutō Unknown Tales arc as an antagonist. He is a former 3rd Seat officer Shinigami of the 6th Division who once revolted against the Seireitei. He was also a member of the Kuchiki noble family, having married into it. He currently goes by the name of Koga Senryu(古賀川柳, Senryū Koga, "old river willow" ) and is now allied with Kire Satoshi and his Liberation Army.

Appearance
Kōga is a tall and well-built Shinigami with very strong green colored eyes, dark purple hair with a long braided pony-tail of rich pink hair, and bangs that hung on the right side of his face to frame it. Back during his days as a Shinigami of the 6th Division, in addition to a standard Shinigami attire, Kōga also wears a long red scarf, light purple obi sash, and a beaded-necklace with a pendant. He also wore an intricate white headpiece called kenseikan on the left side of his head to symbolize his nobility that held his ponytail in place with red tufts of hair sticking out (which he later cut off to relinquish his status as a Kuchiki). While originally his appearance was youthful and fit, after several hundred years sealed away, his physical form has been reduced to a withered-old version of his former self.

Personality
In the past, Kōga was a man with a true sense of duty and a commitment to making his family proud. He always tried to remain humble and serious to situations at hand. On the inside however, Kōga was a man who deeply desired to be acknowledged for his abilities and hard work. After realizing that his life as he knew it was gone forever, he had a mental-breakdown, causing him to become consumed by his anger and desire to stand in greatness, leading him to become immensely arrogant in his power to the point of viewing all others as worthless, even his own Zanpakutō, Muramasa.

History
Several hundred years before the main storyline, Kōga was welcomed into the Kuchiki family as the son-in-law of the Ginrei Kuchiki. He soon gained much respect throughout Soul Society. Unfortunately, the one person Kōga wanted to be acknowledged by, his father-in-law Ginrei, always looked at him with indifference and put him through tests. The only person to ever comfort Kōga at all was his Zanpakutō Muramasa. Kōga later became a powerful ally in a civil war. When it became clear that he may very well be the key to winning the war, the enemies, which included three elites, came up with a plan to frame him as a traitor. He was later freed by Muramasa who inspired him to take control of his life again. Kōga then did so by killing the elites who framed him. But it was only after he did so that he realized he made a mistake. Realizing his life was forever ruined, he went insane and decided that everyone was jealous of his powers, thereby meaning he had to crush all others to stand tall in the world again and soon revolted against the Seireitei. As he killed more people, his instability grew, soon even abusing Muramasa when he was anything less than absolutely obedient. This disharmony between them gradually caused Kōga to lose his ability to communicate with and even access Muramasa's power. Genryūsai Shigekuni Yamamoto and Ginrei Kuchiki were eventually able to seal Kōga away when he lost total access to Muramasa's power. Kōga's revolt was never recorded in the Soul Society's history.

Powers & Abilities
Master Swordsmanship Specialist: Kōga was an immensely powerful combatant, even with only his sealed Zanpakutō. Back when he was only a 3rd seat officer, he was able to easily fight at captain-level and take down a large group of enemies attacking him at once.[2] His skills are very versatile, able to use various bladed weapons with high proficiency.

Flash Step Master: Kōga has demonstrated highly proficient skill in Flash Step, able to keep on equal footing with Byakuya Kuchiki, one of the most skilled masters. In battle, Kōga has shown great enough reflexes to dodge point-blank sword attacks unscathed.

Kidō Master: Kōga's skill in Kidō is immense, able to use various forms of spells with great power and skill; all at the same time without incantation.

Enhanced Strength: Even in his physically withered state, Kōga is deceptively strong. With a single downward chop, he was able to snap his sword's blade in two.

Immense Spiritual Power: While not a noble by blood nor of considerable age, Kōga possessed great spiritual power even when only a 3rd seat officer. Ginrei, the 6th Division captain at the time, states Kōga's power vastly surpasses his own. He displays a massive reiatsu, even after being sealed away for several centuries. His reiatsu is purple in color. His skill and control at using his spiritual energy allows him to perform a variety of abilities.

Zanpakutō
Gin Kiri (銀霧, Silver-Mist): The shape of Koga's new zanpakuto is similar to his old one, though with minor variation. It takes the form of a katana with a dull gray sheath, siver hilt-wrapping and a guard in a shape similar to the Kidō Corps' emblem, consisting of a circle with a pentagon-like shape in the center and three points protruding from the edges evenly spaced apart. Like his previous zanpakuto Ginkiri is an illusion-type Zanpakutō.


 * Shikai: The release command is "Be Silent" (黙る, damaru). Muramasa shines with bright purple light to engulf a considerable radius, affecting any and all targets within it.


 * Shikai Special Ability: Gin Kiri has several abilities in it's shikai form.