Chu Shuzhi works for the SID. He is a Dixingren who can control puppets using strings of dark energy. He is/was a Puppet Master of the Chu Clan.
He had a twin brother, Chu Nianzhi, who died and whom he still misses. He was convicted for a crime (ep35).
The Black Cloaked Envoy has placed him at the SID as a spy.