Who is Father Flannery from Cradle and All and what is their importance?

Father Flannery presides over Colleen's rural church parish in Maam Cross, Ireland. Father Flannery appears to be possessed by the Devil, as rather than being a holy man with a gentle and caring nature, he seems to prey on Colleen. Flannery makes inappropriate comments and gestures toward Colleen, and he is responsible for the deaths of Colleen's mother and Sister Katherine.