While "Digital Devil Saga - Avatar Tuners 1&2 Original Sound Track Kanzentai" has songs from DDS1 that are not on the first DDS1 OST, "Digital Devil Saga - Avatar Tuner Vol.1," does "Digital Devil Saga - Avatar Tuners 1&2 Original Sound Track Kanzentai" however have all the tunes on "Digital Devil Saga - Avatar Tuner Vol.1" though?

Thank you!

Yes, all tracks on the DDS Vol.1 OST are on the DDS 1&2 OST, although some are under different names.

DDS Vol. 1 OST name = DDS 1&2 OST name
Configuration = Never Ending Rain
Karma = Level Up
Hunting = Hunting -Surprise Raid-
End Theme = The Rain Stopped

However, the vocal track Pray is longer on the DDS Vol. 1 OST at 3:09 as opposed to the DDS 1&2 OST version that is 1:43.

Thank you Yatta. Thanks immensely helpful!