This song sounds sick. I downloaded the guitar pro file for it. But question, which album or compilation can this be found on? Am I missing something here?

What is the hardest/most difficult song for you guys to play on guitar? For me it is Fugue simply because of the speed of the downstrokes. Next to follow would be either When All Light Dies or Ember to Inferno.
I can't coordinate myself to play downstrokes that fast, but nevertheless it gives me a hell of a workout just even attempting it. Most of the Ascendancy riffs arent that bad.