Killer B

is a muscle-bound shinobi from Kumogakure and the Jinchūriki of the Eight-Tailed Beast. It is hinted he comes from the Yotsuki clan. He appears to dislike light. On his right shoulder, he has a tattoo that says ; and on his left cheek, he has a tattoo of a bull's horn (correspondingly, the Eight-Tails has horns like a bull, and the left one is missing). He also carries seven swords and has a brother who is the Raikage.

Personality
It seems that he demands respect from others and asks to be called and his Tailed Beast be called. He also appears willing to speak in song, more specifically in rap style, even when confronted with potential threats. He will even stop in a middle of a fight to write whatever rhymes come to him. He has a casual relationship with the Eight-tailed Beast, frequently engaging in friendly conversation with it.

Hunt for the Eight-Tails
Team Hawk, after discovering that the Eight-Tails was training in the Valley of Clouds and Lightning, traveled up to the valley. He revealed himself after appearing to contain his Tailed Beast. When Suigetsu attacked him, he easily overpowered him, and uses Suigetsu's sword to defeat Jugo afterward. He later shows an unorthodox sword style where he manages to hold all seven of his swords in a rather awkward pose, this is deceiving as his seven sword style is extremely formidable and he even fatally wounds Sasuke Uchiha as Sasuke could not track the sword movements even with his sharingan.

As he moves in to finish Sasuke, Suigetsu comes to save him while Jugo attacks from behind. Even with the three fighting him at once Kirābī appears unfazed by their attacks. When the three do a triple damaging attack to him, he somehow moves extremely quickly to a safe position relatively far away. Finally getting annoyed with Team Hawk, Kirābī decides to go home and have some whiskey, but Karin senses his location. As Sasuke is rocketed to his position, Kirābī announces he will unveil the "Eight One". Kirābī developed his own demon chakra shield, similar to Naruto's chakra shield, and proceeded to attack Team Hawk. Sasuke then attempted to place him in a genjutsu but as Sasuke lowered his guard, Kirābī struck. In the end, he blasted a hole in Sasuke's chest and neck claiming that a Jinchuriki that has full control of his beast can become immune to genjutsu. Annoyed with Team Hawk, he finally completely released the full power of the Eight-Tailed Beast, ordering the team to cower in fear of him, something they did.

After the Eight Tails was hit with Sasuke's Amaterasu, it transformed back into an unconscious Kirābī. With his defeat, Sasuke carries him away. After Kirābī is kidnapped, his brother, the current Raikage, is totally outraged. He sends out some Cloud Ninja to stalk Team Hawk. The first one, Jei, is captured by Sasuke and Jugo (it is unknown if they killed him or not). Three more are sent out after him. This second team includes Samui, Omoi, and Karui. These three are apparently his students.

"Vacation"
While sealing the Eight-Tailed Beast, Kirābī's body transformed into the tentacle that Sasuke had severed during the fight. It is revealed that the real Kirābī had replaced himself with that tentacle and used the entire fight as a ruse to escape his village, where he had grown bored of being a guardian. Since his village now believes him to be captured, he uses this as an opportunity to take a "vacation" from being a guardian. As Eight Tails comments that a new era is coming, Kirābī thinks he means about his new music career.

Abilities
His physical strength and taijutsu skill is immense. He is easily capable of disarming a skilled opponent with his bare hands, and proficiently wielded Suigetsu's huge sword seconds after picking it up. His specialty, however, is wielding his seven swords, which he does in an odd way, holding them in between the joints of his arms and left leg, his stomach and the left side of his neck. As strange as it appears, he is quite skilled with this, spinning around like a buzz saw and overwhelming his opponent with all of the varying swings. He is also capable of seamlessly releasing some of the swords to fight in a more conventional style, giving him great versatility. When he does find an opening, he can impale his opponent with most of his swords at once. While fighting with this style, he was effortlessly able to defeat Sasuke after dealing him a mortal blow. His defense is fairly strong, able to easily withstand attacks from Sasuke's Chidori and Jugo's powered-up arm without any sign of damage.

During the battle with Sasuke he displayed the ability to flow chakra through his blades to increase their cutting power similar (if not equal) to the Chidori Current does with Sasuke's Kusanagi Sword. He is able to conduct his own lightning element chakra into his swords and give an electrifing blow.

Like Naruto, Kirābī also has the power to create his own chakra cloak when drawing on his demon's power without much effort. It is because he has control over his own demon, he is able to break Sasuke's Mangekyo Sharingan genjutsu because he used the Eight-Tails to disturb his chakra. Like his fellow Cloud kunoichi, Yugito Nii, he is also able to become his Tailed Beast itself with great ease.

Trivia

 * His Sword style is reminiscent of Roronoa Zoro's Santōryū in One Piece (a fellow Shonen Jump manga) in that he uses an odd number of swords as well as holding a sword in his mouth.
 * He quoted Muhammad Ali's famous line, "float like a butterfly, sting like a bee".
 * Though not his confirmed name, Kirābī was given a fan name of Kira Hachi, the word "Kirābī" incorrectly translated into Japanese (Hachi is the Japanese word for "bee". Kira is a loanword of the English "killer").
 * Kirābī has a unique personality, similar to black urban youth stereotypes (corn rows, jive talk, and rapping). This could also either be a homage or a reference to the Wu-Tang Clan, who are martial arts enthusiasts. He calls himself the Kirābī - an old "Wu Tang" Kung Fu movie and group name of Wu Tang Records. Most members and groups of this label get their stage name from the old "Wu Tang" movies (Ex. Method Man, Old Dirty Bastard, RZA, GZA, Kirābīs, and the records labels name itself).
 * Kirābī makes various references to bees. This is a pun on the number of tails his Tailed Beast has. Eight in Japanese is, a homophone to the Japanese word for bee,.
 * As a unintentional pun, the fan name Kira Hachi, can be translated to "Killer Eight", following the homophone of bee.

Quotes

 * I was right in the middle of an announcement, you stupid idiot!
 * I'm the only one who gets to interrupt me!
 * Shut up-o! Yes I am-o!
 * I've got energy to spare and sparkling charm. The eight tailed beast's a killerbee rockin the melody! OH YEAH!
 * Check it out, yo!
 * All right, time for a number eight! WHEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE!!!!!!!!!!!!!!!!