Shachi is the son of Akashachi, the pirate. Shachi was left behind in Asura after Akashachi fled during an attack and there he became romantically involved with Leia, a local girl. He became Jukei's fourth student and learned Hokuto Ryūken to protect Leia. He began fighting against the Asuras, eventually earning a reputation as "Rakshasa". At first, he only teams up with Ken to use him in his plot to destroy the three "Rashō", allowing Lin to be captured by Kaioh so that Ken would fight him.

(Source: Wikipedia)