Leonard's Incorruptus armor is pretty awesome. It's also really cool to watch it in action.
Seeing all of Balandor's and Faria's air forces and navy going after the Yshrenian's was incredibly badass.
The Avatar's fight with Madoras. For whatever reason, he's still capable of using the White Knight, and it comes complete with a Theme Music Powerup. After all that time sitting in the background playing the Humble Hero, your avatar takes center stage and finishes off the villain once and for all!
Origins opens with the player character rushing the freaking White Knight bare-handed.