Kyōbōna Sorasenshi

Kyōbōna Sorasenshi (空の戦士凶暴な人, Sorasenshi Kyōbōna; Japanese for Berserker of the Sky Warriors) is a member of Getsugakure's high-ranking Sangekkō organization, specializing in Kinjutsu along with the other members. He utilizes kinjutsu that allow him to negate or nullify the effects of heavy wounds, increasing his battle potential. He is treated as a jonin of the village, but is not recognized by such by other villages, having never gone through official ninja training, instead discovering kinjutsu through his own research and Orochimaru's. He was once a scientist for Orochimaru, who informed on him to the Hokage, revealing his experiments, and inadvertently became the victim of several kinjutsu, developing them into a fighting style. Due to exposure to dangerous gases while spying on Orochimaru, he fell into a state of suspended animation for many years, and so appears, mentally and physically, much younger than he is.

Appearance
Kyōbōna is noticeably tall, almost equalling Kojimaru Sensōkajiya in height. He is a very markedly prominent figure, with a high brow and black eyebrows with spikes extending from them. He has eyes with large black irises, and appears to lack pupils entirely. He has a cross-like symbol tattooed permanently onto his forehead, centered around a dot encased in a diamond, with lines exiting all four sides of the diamond and ending in leaf shapes. His hair is black and kept low to his head, though it often flares up into three distinctive backwards-aiming spikes. He wears gold-ringed earrings in the shape of blue water droplets on both his ears, and wears a black jacket with white fur decorating a large collar. His clothing is black and dark blue, and he wears a cloak at most times.

History
Kyōbōna was born into a world of blood, as Orochimaru used his father as a test for a poison that caused him to go insane, killing Kyōbōna's mother and himself even as the newborn babe screamed next to them. He was sent to Getsugakure to be raised as one of their own, due to superstitions about the misfortune of such a birth, and the Third Hokage's realizing that he would not be welcome in Konoha due to the circumstances of his birth. Eventually, when the Third Hokage began to look into the mysterious disappearances in Konoha, Orochimaru decided that he needed an assistant in another village to cull subjects without notifying the Hokage, and it pleased him to ironically choose Kyōbōna, still a boy of only ten, whose life he had already shaped. Kyōbōna, however, figured out from records of Orochimaru's what had been done at his birth, and ended up spying on Orochimaru and betraying him to the Hokage, resulting in Orochimaru's exile from Konoha. Remaining in Getsugakure, he took ill some time later, and after transport to Konoha's more advanced hospitals, where Tsunade, who had not yet left Konoha, treated him and discovered that he had been affected by gases in the laboratories where Orochimaru had made him work. Unable to completely nullify the gas' effect, she used all of her skill to counteract it slightly, placing him in an extended coma and state of suspended animation rather than allowing the gas kill him. She eventually decided that she was unable to save him, and left him in that state, rather than give up entirely. Eventually, when she returned to Konoha as the Fifth Hokage, she was able to use her much-improved skills to revivify him, reversing the coma and bringing him back the same as the day he had been placed under the coma. He returned to Getsugakure after pledging her his eternal servitude if she should ever need it.

Some time later, it was discovered further through analysis of the gas that it could not have been completely removed, and Kyōbōna was recalled to Konoha for further testing. Indeed, it was still dormant in him, and Tsunade deduced that every seven years he would enter a similar coma-like state for one month, at which time he must return to Konoha. It was also discovered that it was warping the chakra in his left arm, though she could not predict how this would turn out. Once again thanking her, he returned to Getsugakure, and experimented on himself in order to be able to control the effects of the gas. Realizing that it gave him a kinjutsu, he studied scrolls of other kinjutsu which he had secretly kept after deserting Orochimaru, and became a member of the Sangekko.

Taijutsu Master
Despite not having trained as a ninja until a later age, Kyōbōna was trained as a child by various masters that he hung around, pestering until they taught him some of their martial art. Because of this, he was able to flourish as a martial artist, pretending to know nothing in order to make it seem to the masters like they weren't giving any of their technique away, when in reality he was a master of a vast number of martial arts. When his hand was cut off in a surprise attack by invading ninja seeking to disable Getsugakure's best fighters, he simply reacted with utmost speed, smashing his newly hewn stump into the attacker's face with full force, breaking his nose and allowing him to defeat him with a bone-shattering kick, quickly enough that medic-nin were able to reattach the hand.

Kinjutsu
Kyōbōna is most powerful in the area of kinjutsu, having been affected by a body-altering smoke of Orochimaru's, and making himself the victim of several other kinjutsu in his attempts to become a powerful ninja. Because of this, he became a ninja, and became highly adept with his kinjutsu techniques.

Using the Humanity Nullification Technique, a kinjutsu he himself invented via expanding Orochimaru's research into the gas which eh was infected with, in an attempt to stop the odd sensation in his arm, Nigihayami can halt all pain that he feels, and if he uses it on a greater scale, all sense of feeling as well, using his chakra sensory skills to discover whether he has made contact with something. This makes him a very highly formidable opponent, because while he may take serious or even life-threatening injuries, he feels nothing, and is able to continue fighting even if he loses a limb. This also lets him overcome any fear of injury, so that he can fight without inhibition, demonstrating far greater destructive power while using this technique. This removes most of the limitations on fighting ability, making him a far more dangerous taijutsu user.

His other kinjutsu are centered around avoiding being crippled or disabled by injury. His Casualty Puppet allows him to absorb others' energy and their body material, often using their hearts as decoys for the Chakra Thread Technique, though he cannot replace his own heart. HIs Soul Void Robbery is used frequently to replace his own missing parts with those of others, making it a healing and offensive technique.