Seiryuu  

, 青龍

Seiryuu is one of the four beasts and possesses dragon-demon characteristics. he's incredibly fast and can use youki to turn his opponents into ice. in the manga, he was quickly defeated by hiei before attacking him, making him the swiftest-defeated saint beast. despite this, in the anime, seiryuu proved to be a formidable opponent, nearly defeating hiei before ultimately perishing himself. he falls under the middle c class of demons.