Barron was a Shadow Lord servant who served Chieftain Farr of Dorne, using his influence in Farr's advisory council to aid in his master's plan to conquer the island.
At some point Barron sold himself to the Shadow Lord in return for magic and power. He then infiltrated Chieftain Farr's advisory council so that he could use his influence there to aid his master in its plan to invade Dorne.
The Third Door
Barron was a beefy, stout, red- and plump-faced man. When Rye first saw him, he was wearing a blue velvet coat and frilled shirt with a high collar, which he had been furtively tugging at as if it was strangling him. He wore a gold earring in his left ear.
When transforming into his monstrous form, Barron's features would melt and reform, his body and skin would swell, thicken, bulge and split till it were shapeless masses of rough bark with tongues of white fungus sprouting from it. His eyes would green holes, his hair would brighten, standing out from the head like crackling flames and his hands gained great, thorny claws.
Barron had been given magical powers by the Shadow Lord and was able to transform himself into a hideous humanoid monster with bark for skin.