Endless Battle

 is Track 29 on the Xenosaga THE ANIMATION Original Soundtrack. It plays in the following scenes:
 * The Woglinde's captain is updated on the battle just before the bridge is destroyed in Episode 2.
 * Pellegri's ship starts its attack on the Elsa in Episode 3.
 * Jr. gets into his A.G.W.S. as the Gnosis surround the Durandal in Episode 4.
 * Macrophages surround the party after they land in the Encephalon in Episode 7.
 * Virgil confronts the E.S. Issachar in Episode 8.
 * Virgil joins the fight against the Gnosis in the Kukai Foundation in Episode 9.
 * KOS-MOS expands the PT cannon into its full size in Episode 10.
 * The Proto Merkabah annihilates an A.G.W.S. squadron in Episode 11.
 * The Proto Merkabah's boosters start sending it towards Second Miltia's atmosphere in Episode 12.

The melody at 2:26 is based upon a motif from Xenosaga Main Title.