Who is Pi Ying from Welcome to the Monkey House and what is their importance?

Pi Ying is the Communist guerilla chief, who controls the area where Kelly's plane crashes. He is apparently under the influence of Major Barzov as a political pawn. Even during the chess game, he appears to change after receiving comments or whispers from Barzov. Pi Ying takes delight in the chess game and in every display of anger or despair from the Americans. His pleasure, however, ends up blurring his vision, and he falls for Kelly's trap when he takes Jerry off the board.