Dissidia Duodecim Final Fantasy EXTRAS Cosmos

Cosmos is the 5th track off the official Dissidia Final Fantasy Original Soundtrack, and was composed by Takeharu Ishimoto and was arranged and performed by the band Your Favorite Enemies.
The song (Cosmos) itself is actually taken from another song by Your Favorite Enemies entitled The Messenger. Lyrics from The Messenger are incorporated into Cosmos.
Although The Messenger itself doesn't play or appear in-game, the original song was featured on the official Dissidia Final Fantasy Original Soundtrack, track 25 on the 2nd disc.