I had a thought about this album earlier today: it's really cool how the album uses styles and instrumentation to represent characters. The instrumentation thing is pretty common, but using musical styles to represent different characters and ideas is something that's definitely a more modern and recent development. Nafaryus being represented by "old" styles like late renaissance instrumental music (A New Beginning), dixieland (Three Days), and tango (Lord Nafaryus) is probably the most obvious example. But there's loads of others:
Faythe is typically associated with a wordless soprano voice solo (i.e. Act of Faythe, The Walking Shadow) and more "ethereal" musical elements (Ravenskill, The Walking Shadow)
Ahrys is typically linked to march rhythms and giant wordless "gospely" choruses. Generally big "military" or "American Civil War" kind of sounds. i.e. A Better Life, Brother, Can You Hear Me?, etc.
Ravenskill seems to have a light association with solo violin. i.e. Hymn of a Thousand Voices, A Better Life
Daryus (or possibly the GNE in general) is linked to the atonal electronic NOMAC tracks and the weirder synth moments (like the synth solos in Disc 2).
Gabriel seems to have a light association with acoustic guitars. It's not 1-1, of course, but a lot of the Gabriel-focused tracks have heavy use of acoustic guitar.
Also, the musical elements that represent Ahrys and Nafaryus seem to be closely related. They're typically represented by "older" styles of music and a heavy use of choruses. Ahrys/Gabriel (and Ravenskill) seems to be more musically rooted in folk elements, like the bagpipe in A Tempting Offer, marches, solo violins, acoustic instrumentation, and more gospel-oriented choruses. Nafaryus/Daryus (and the GNE), on the other hand, is rooted in the more "sophisticated" tangos, renaissance music, and dixieland. His choirs are also more "classical", and use words more often. And, in contrast to the heavy use of acoustic guitars and hammonds in Ravenskill tracks, the GNE ones focus more on electronic instrumentation. Also, both Ahrys and Nafaryus are frequently associated with trumpet fanfares.
idk how intentional all of this is, but it's really cool nonetheless!