Although you're only involved in the design aspect of the KHI game project, I thought you might be interested in knowing that I've begun work on an overworld theme for Prydain--which spawned a separate theme for the Horned King himself.
I'm try to include some motifs from The Black Cauldron 's score as well, but it's much more difficult to use software than to improvise on a piano. Either way, look for both MIDI files in the world and character threads, respectively.