Who is Sabin from The Killing Dance and what is their importance?

Sabin is a master vampire. He travels to St. Louis from Europe under the guise of requesting Anita's assistance to heal a degenerative disease, which is a result of refraining from human blood. In actuality, he intends to use Anita, Richard and Jean-Claude in a spell that his human servant, Dominic Dumare, has discovered that will restore his health.