http://youtube.com/watch?v=EcInBA4FlU8Die Rache Krieg Lied der Assyriche by Nile.
There's something very angry and primitive about this little song!
One of those songs that just begs to be used in a montage! It's like angry pagan version of Eye of the tiger. Instead of training to beat Apollo, you'd have to behead people while spitting out cheesy Cthulhu one liners tho.