Who is Homir Munn from Second Foundation and what is their importance?

Homir Munn is one of the five conspirators and an expert on the Mule. He is sent to Kalgan to garner additional information on the Second Foundation. Stettin, however, quickly discovers his intent and holds him prisoner while a war rages between Kalgan and the Foundation. Kalgan later releases him and sends him back as a peace envoy. Once he is back amongst the Conspirators, Homir claims the Second Foundation doesn't exist, but after giving him a brain scan, Dr.Darrell discovers the Second Foundation has conditioned his mind.