Battle Start

 is Track 3 on the Xenosaga THE ANIMATION Original Soundtrack. It plays in the following scenes:
 * KOS-MOS attacks simulated enemy forces in the KOS-MOS Simulator in Episode 1.
 * Ziggy attacks KOS-MOS as she boards the Elsa in Episode 3.
 * Tony wave-rides the Elsa to escape Pellegri's ship in Episode 4.
 * A program targets the party and withstands Ziggy's and Jr.'s attacks in the Encephalon in Episode 7.