If anyone is looking for the Goblin Prince to complete their bestiary, I just ran into two in a large party of green goblins (goblin guard I think they're called), and they're called DesAngel in the nes fanslation for some reason xD I assume it's the same beast because the sprite colors are identical white and blue. Anyways, you don't have to be inside kashuon castle, the plains to the west was where I ran into these.