Suikotsu

was a member of the Shichinintai. Like the others, he loved carnage and killing; however, unlike them, he had a split personality. This personality was that of a kind-hearted doctor, who may have been the original personality until a traumatic event caused the birth of his other, more bloodthirsty, personality.

History
Suikotsu is a killer who suffers from multiple personality disorder. He has two, definite split personalities. One a gentle, philanthropist doctor who looks after orphans, the other a psychopathic and sadistic thrill killer with a Wolverine-like appearance that earns him his spot in the Band of Seven. When his evil side takes hold, he seems to possess a dry sense of humor and an insatiable desire for blood, while when his good side is in control, he often hallucinates that he has blood on his hands. He may have a third personality, as shown after he falls off a rope-bridge; this personality seems to be a combination of his other two. Doctor Suikotsu develops a close, empathic relationship with Kikyō.

When his evil side is in control, he has six green tiger-like markings on the edge of his face. The markings are strikingly similar to what a general evil character has painted on their face in Japanese opera.

Death
In both the anime and manga, Suikotsu dies after a battle with Kikyō and Sesshōmaru, the latter of which decided to fight him after he kidnapped and threatened to kill Rin. After suffering a fatal attack, he asks Kikyō to remove his jewel shard from his neck so that he can die peacefully. Sadly however, Jakotsu violently removes the shard instead.

Abilities
When he is good, Suikotsu is a skilled healer who can make several remedies with various herbs for various injuries. He is often compared to a saint.

While his evil self is out, he has athletic attributes that rival those of Bankotsu & strength that rivals Inuyasha. He wields a pair of Tiger-Claws. He also claims to be an expert of close-range combat.

Quotes

 * "That good for nothing doctor, keeping me down for so long..."
 * "I'm sorry, but you're not going anywhere. You're mine, because, you see... I can't stand monks or doctors!"
 * "Jakotsu... I can do it now, right? I can kill this little bitch?"
 * "My evil side, I-I've killed so many, and I couldn't do anything to stop it. I can't stand the thought of letting it happen all over again. Please, Lady Kikyō, remove my shard, turn me back into bones, save my soul, I beg of you..."

Trivia

 * The evil Suikotsu's eyes look much like slits.
 * His eyebrows also disappear when his evil personality surfaces.
 * Suikotsu bears a resemblance to Dr. Jekyll and Mr. Hyde, as the good half is a doctor while the evil half is a mad killer.
 * The evil Suikotsu's "claws" and hairstyle look similar to Wolverine's from X-Men. He has even copied some of his more well-known poses, such as crossing his arms over his chest or spreading his arms apart.
 * Suikotsu's name comes from two kanji (睡, "Sui"; 骨, "Kotsu"), and is translated as "sleeping skill," possibly referring to his "sleeping" personality.
 * The tattoos on 'Evil' Suikotsu's face mean Rage, refers to him being the dark side of Suikotsu.
 * The blades of his tiger-claws have constantly changed their size, from being the length of the glove/handle, to being three times as long. The angle of the blades are also inconsistent.
 * Suikotsu's seiyū, Hirata Hiroaki, also voices Sanji in the Japanese version of One Piece, as well as the tokubetsu jōnin Shiranui Genma in the Japanese version of Naruto and Shippūden. His English voice actor, Michael Donovan, voiced Wolverine's primary villain/rival Sabretooth in X-Men: Evolution.