I haven't thought much about this before! When I'm drawing Polyphemus I tend to listen to the entire Public Service Broadcasting discography, but I'm not sure that fits... It's a bit more spacey than my comic. d: Possibly Valentina by them. Maybe something by Two Steps From Hell? Rise Above isn't too bad...
I think something that starts off happier though, and progresses into an epic fantasy soundtrack kind of thing.
The first two of these aren't bad, either!