Kaijinbō

was a former apprentice of Tōtōsai and later forged Tōkijin at the behest of Sesshōmaru.

History
Under Tōtōsai's wing, Kaijinbō crafted weapons housing great and sinister powers. He once killed ten innocent children in order to craft a sword. Disgusted by the results of his works, Tōtōsai banished him. Even then, he continued his work in spite of him.

During the Story
Despite his short appearance in the series, his swords affected many in the long run. He was most pivotal in Sesshōmaru's quest for power, after being commissioned with the task of creating a very powerful sword, one that would rival the Tessaiga, which came in the form of Tōkijin. Created from the fangs of Naraku's third incarnation, Goshinki, the blade seethed with a terrible aura that eventually overcame Kaijinbō and took over his body. Drowning in its power, Kaijinbō attacked Inuyasha, for Tōkijin craved for the half-demon's blood. Kaijinbō was eventually struck down by Inuyasha as his entire body was obliterated in a clash. Sesshōmaru claimed the sword for himself shortly after. In the anime before his death, Kaijinbō created another powerful weapon known as the Naginata of Kenkon, a naginata weapon commissioned by the demon Hoshiyomi.

Personality
Unlike Tōtōsai, Kaijinbō was a rude, ruthless demon, who felt no remorse for his heinous actions (Like killing children and using their flesh to forge a sword) and even claimed that he could make stronger swords precisely because of his lack of goodness. He was also vengeful, as he accepted to forge a sword for Sesshōmaru upon hearing that he could use the fangs of Goshinki, which destroyed the original Tessaiga, a work of Tōtōsai.

Physical description
Kaijinbō was a humanoid demon with light orange skin and small horns on his head. He had fangs, black hair and small mustache and weore a grey shirt and a necklace made from skulls. When he's possessed by Tōkijin, his eyes wee blank and occasionally glow red.

Powers and Abilities
Master Swordsmith: Kaijinbo had great skills in forging demon swords as he was the former disciple of Totosai himself. Due to the lack of morals in how he worked, Sesshomaru noted his creations were seethed in great hatred and power, but this could cause great danger to the wielder and even himself.

Creations

 * Tōkijin for Sesshōmaru
 * Naginata of Kenkon for Hoshiyomi

Trivia

 * His seiyū provided several voices for Rumiko Takahashi's previous work Ranma ½. They include Kinnii, The Gambling King, and Shinnosuke's grandfather.
 * His english voice actor also voiced for Ranma ½. Most notably for voicing Genma Saotome.