Although this song only plays while you're marching your troops towards the enemy, it really sets up the mood for the bloodshed that's about to happen.
jugding by my first reaction to the music upon heraaing it, i would have have to say the music for the final two battles with sepheroth. The wings form (second part) and the final one vs one battle.
idk I like the "intense" battle music you wouldn't expect from a game like Pokeymans or Kirby, you sorta expect it from a FF game or whatever, so that sorta demeans it (for me anyways)