Saika (雑賀) is the leader of The Faction, a group of warrior monks who travel around the Fire Country and its bordering nations.
A kindly old man, Saika only wishes for peace despite being the leader of his group of monks. He values life over anything else on the planet, being a complete vegetarian. He even tried to save Haku by giving some of his life force to the group's healer to assist in reviving the dying boy. He also tries to teach all he knows to those who will listen, loving being a tutor.
There is one thing he will not stand for: those who would readily harm another without reason. He will temporarily lose his self control and do all in his power to bring the offender to swift justice.
Saika, being a warrior monk, has a variety of techniques and jutsu at his disposal that only monks know. First and foremost he is skilled at using tanto. His skills are so great that he is able to use two at once and do handseals while attacking with them. His two primary monk jutsu are Vermillion and Swift. The former extends his tanto's reach to that of normal swords by utilizing his chakra. The latter increases his speed with chakra while he rapidly slashes nearby enemies. His last technique is a ninjutsu he picked up from the ninja monks in the Wind Temple, Wind Style: Tamonten, which creates a windy visage of the war god of Buddhism, Bishamonten, that surrounds and protects him. He can then proceed to use it to attack using the visage's arms and sword.
In Haku Gaiden, Saika is the leader of the Faction at the time they find Haku, dying at the side of his grave after digging himself out. He orders his followers to heal him and take him with them. He oversees the boy's recovery and tries to teach him the ways of a monk. While Haku is receptive, he eventually decides he must part. Saika reluctantly allows him to go, wishing the boy luck.