This is a truly wonderful piece of music, rich and complex, all the more surprising for coming from Kingdom Hearts -- which amounts to "What if Disney's animated universe collided with Final Fantasy?".
This piece is one of the primary themes for The Arena -- one I played often while writing Grand Central Arena, Spheres of Influence, and Challenges of The Deeps. It has multiple movements that cover the adventure, grandeur, peril, and awe of the Arena, ideal for me writing many different scenes within that most awesome of constructs. Listening to it I can picture all of the characters and their finest moments -- both those you've seen, and many of those yet to come.
If I were to choose any ONE piece to represent The Arena, this is the one.