Realian's Sorrow

 is Track 7 on the Xenosaga THE ANIMATION Original Soundtrack. It plays in the following scenes:
 * MOMO comforts Jr. after he explains how he abandoned Albedo in Episode 8.
 * MOMO sees Kirsch's memories of Joachim Mizrahi in Episode 10.
 * Kirsch has a heart-to-heart with Albedo before the party arrives in Episode 11.