Who is Sergeant Mori Luk from Foundation and Empire and what is their importance?

Described as the perfect soldier as he is blindly obedient and wildly dedicated to his leader, Luk allows himself to be taken in by Devers when the trader gives him a personal freezer to send home to his wife. Luk then sneaks books in to Devers and Barr and is the one who tells them that Brodig is going to visit them the following day. It's also Luk who encounters Devers and Barr as they are escaping to Devers' ship.