Killer B

is a ninja from Kumogakure and the Jinchuriki of the Eight-Tailed Beast. He is a black, musclebound Cloud shinobi, who appears to dislike light. On his right shoulder, he has a tattoo that says "iron"; and on his left cheek, he has a tattoo of a bull's horn. He also carries seven swords.

Personality
It seems that he hates being called the host for the Eight-Tailed Beast, and prefers to be referred as "me and that thing." 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 spits "Hot Fiya".

Hunt for the Eight Tails
Team Hawk, after discovering that the Eight Tails was training in the Unroikyo Mountains traveled up the mountain. Kira Hachi revealed himself after appearing to contain his tailed beast. When Suigetsu attacked him, Kira Hachi easily overpowered him, and uses Suigetsu's sword to defeat Jugo afterwards. He later shows an unorthadox 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 fatally wounds Sasuke.

Abilities
Kira Hachi appears to be able to fully transform into his Tailed beast with great ease, similar to his fellow Cloud shinobi, Yugito Nii.

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 giant 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 awkward as it appears, he is quite skilled with this, spinning around like a buzzsaw and overwhelming his opponent with all of the varying swings. When he does find an opening, he can impale his opponent with most of his swords at once.

During the battle with Sasuke he displayed the ability like Sasuke to conduct Chakra down his blades to increase their cutting power like Chidori Current does with Sasukes Kusanagi Sword.

Trivia

 * His Sword style is reminiscent of Roronoa Zoro's Santōryū in One Piece, a fellow Shonen Jump manga.
 * He quoted Muhammad Ali's famous line, "float like a butterfly, sting like a bee" in chapter 411