The Black Dragon God was both a god and a political leader. He was the nominal ruler of the Black Dragon Cult.
He attacked the major kingdoms of the planet because its denizens had an alcohol-driven lifestyle. (Star Trek: The Stoneship Files: "Alcoholic Massacre, Part I")
The current Black Dragon God was called Mehm. It employed an abomination named Arylon, the Faithless King, as a general to command its forces. The Cult was defeated when Volanus, the capital city of the Cult, was destroyed by a Feudeymon spell. (Star Trek: The Stoneship Files: "Alcoholic Massacre, Part II")