I have defended
Dancing Mad as the greatest final boss theme for years. I don't even have to explain why, either; the song does it for itself.
I also really enjoyed
The Battle for Everyone's Souls. It's good that the song is really catchy, because Nyx Avatar is one hell of marathon boss. But what gets me is how neatly
Aria of the Soul is mixed in toward the end.
Id (Purpose) is absolutely perfect in every way imaginable. The buildup to it is perfect -- it's a quieter, more distant version of
Id (Purpose), but when it stops and the song truly begins, it sends of jolt of adrenaline through my body and makes me want to carry the day just one last time.
... I just really enjoy leitmotifs in my music, okay?