Chin, Yisou

清一色

The son of Hyakugan Maoh. As a centipede youkai, he possesses the ability to control centipedes, but he was also proficient in Yin-Yang arts, using Mahjong tiles as mediums to command shikigami. He was the youkai who served as the catalyst for Hakkai's transformation into a youkai, and he lost his life once at the hands of Gonou. Just as he was on the brink of death, he buried a Mahjong tile within his own body, turning his corpse into a shikigami. He never saw eye-to-eye with his father, Hyakugan Maoh, so they were not close. Overcome by the need for revenge for the killing of his entire clan and himself, he demonstrated an almost abnormal fixation on Hakkai during his psychological attacks on the man. He is like a sinister reptile with a clingy temperament.
Incidentally, the objects he held in his mouth like a cigarette are Mahjong counters. They can also be thrown like needles. The name Chin Yisou was one he gave himself after becoming a shikigami. It is the name of a Mahjong combination, as well as carrying the meaning "to be dyed in one color".
Chin Yisou, or the single suit hand, refers to "All tiles in the hand are exclusively of one suit with no honor tiles". Chin Yisou also controlled a huge crab-like shikigami, but impact-wise, nothing can beat this creepy China-boy style puppet familiar. He cackles and spits seed beams from his mouth. It did not come up in the manga, but his name is Ryuu Yisou.