Rinku
Rinku is a child-demon who uses yo-yos to attack and is a member of the Jolly Devil Six in the Dark Tournament. Rinku is childish and playful, although this tends to annoy those around him. He is also, apparently, good friends with fellow member Chu. Rinku can manipulate special yo-yos called Serpent Yo-Yos. Using his aura, he can control their movements, and can either entangle his enemies or strike them. In the Makai Tournament, Rinku learned the ability to also use his toes as well and his fingers to control the yo-yos. According to Kuwabara, he also has an extremely powerful kick. In the Dark Tournament Preliminaries, he fights against Kuwabara, and wins when both contestants get knocked off the arena, with Rinku getting back up and using his yo-yos to ensnare Kuwabara, who can't get back on. Rinku then makes several minor appearances after that, such as the fight between Yusuke Urameshi and Younger Toguro. In the Saga of the Three Kings, he trains under Genkai and becomes an A-Class demon. In the Makai Tournament, he passed the preliminaries, but didn't make it very far after that.