Haragiri

Haragiri (ハラギリ, Haragiri) was a swordmaster and a member of the Council of Swordmasters, before deciding to join the Monster Association.

Appearance
As a human he had his long dark hair slick back and a prominent widow peak. His attire consisted of a sleeveless haori over his kimono. He carries a katana sheathed away in a scabbard found on the left side of his hip. When in his monster form, his skin becomes darker and a third eye can be seen on his forehead. His teeth becomes sharper and his hair turn lighter in color.

Personality
Haragiri is a very blithe individual who is mostly concerned about improving his swordsmanship. In exchange for his lust for power, he completely abandoned his humanity and joined the Monster Association. After becoming a mysterious being, he became very arrogant as he believed that he could easily kill Atomic Samurai whom is one of the highest ranked S-Class hero.

Monster Association Arc
During the meeting of the Council of Swordsmasters, while Atomic Samurai was thanking the other members for their support in chasing down the "Human Monster", Garou, Haragiri interrupts Atomic Samurai and reveals that he joined the Monster Association who offered, in return for giving up his humanity, a power far beyond that which He currently possessed. He agreed and ingested a Monster Cell, turning himself into a mysterious being. During the meeting of the Council of Swordmasters, he threatened to kill all four members unless they ate one of the Monster Cells and "monsterize" themselves. As he was about to kill Atomic Samurai, after giving him 3 seconds to eat one of the Monster Cells, he was cut into pieces by Atomic Samurai's blade.

Abilities and Powers
Haragiri was a member of the Council of Swordmasters while human and thus had masterful and high skills in swordsmanship and his transformation into a mysterious being heightened his power though not enough to compete against the likes of Atomic Samurai.

Supernatural Abilities
Transformation: Haragiri gained the ability to transform his physical form after becoming a monster as he ate a monster cell prior to the meeting with the Council of Swordmasters yet only when presenting them to the other members did he reveal his monster form.

Physical Abilities
Immense Speed and Reflexes: Prior to his transformation into a monster, Haragiri claims that he can cut at speeds faster than the speed of sound.

Immense Strength: Due to the fact that he was a member of the Council of Swordmasters, it can be assumed that he has immense strength, however even with his transformation he was still outmatched by Atomic Samurai

Fighting Style
Master Swordsman: As a member of the Council of Swordmasters, Haragiri was no doubt a powerful swordsman though was outmatched by Atomic Samurai.

Equipment
Katana: Haragiri was shown to possess a katana that he intended to use to kill the members of the Council of Swordmasters

Trivia

 * Haragiri stands for seppuku in Japanese.