"Paradox" is the theme in Final Fantasy XIII-2 representing the paradox effect played throughout the story. Composed by Naoshi Mizuta, it features a fast paced haunting orchestral melody. Behind the main theme "FINAL FANTASY XIII-2 - Wishes -", it is the second most recurrent theme in the game and has many arrangements.
"Paradox" is the eighth track of the original soundtrack's first disc. It plays at the beginning of Episode 1, during the prophecy of Cocoon's fall in Yaschas Massif 01X AF, and after Serah talks to Snow in her dream in the Void Beyond.
The "Paradox" motif is rearranged in twelve tracks: "Giant's Fist", "The Story So Far...", "Paradigm Shift", "Song of the Farseers", "Oracle Drive", "Eyes of Etro", "Oathbrand", "Plains of Eternity", "Threat Level Omega", "Yeul's Theme", "Time's Master", and "Promise to the Future". It is also featured in the "Closing Credits". All of these tracks were also composed by Naoshi Mizuta.
"Giant's Fist" plays during the series of battles in New Bodhum 3 AF at the beginning of Episode 1, the battle with the first Gogmagog and the battle with Atlas. "Paradigm Shift" is a frequent battle theme that plays during random encounters. "The Story So Far..." plays when Mog speaks for the first time in the Bresha Ruins 5 AF, and during the story recaps that follow loading a save file.
"Song of the Farseers" is an arrangement played with acoustic guitar and features vocals. It plays in the Yaschas Massif 010 AF after Hope tells Noel and Serah about the Farseers, after Hope induces a vision of Lightning and Caius's battle in Valhalla with the Oracle Drive, and during the boss battle against Pacos Amethyst and Pacos Luvulite in Academia 500 AF.
"Oracle Drive" plays when Noel uses the Oracle Drive in Yaschas Massif 10 AF, and when he, Mog, and Serah first enter the Coliseum. "Eyes of Etro" only plays during the cutscene before Noel and Serah leave Oerba 200 AF after their battle against Caius. "Oathbrand" is a darker version of "Paradox" that plays at the beginning of Episode 3, and when Alyssa betrays Noel and Serah in Academia 4XX AF.
"Plains of Eternity" is an electronic pop song with vocal performed by Joelle and mixed by GOH HOTODA that features the "Paradox" motif, and is the background theme for the Archylte Steppe during sunny weather. "Threat Level Omega" is the background theme for Academia 400 AF. "Yeul's Theme" is the leitmotif of Yeul with vocals performed by Joelle, and plays when she dies in the Yaschas Massif 1X AF, Augusta Tower 200 AF, in the Dying World 700 AF after Caius and Noel's fight, and when Yeul dies in that time. "Time's Master" plays during the boss battle against Chaos Bahamut and Caius in Academia 500 AF.
"Promise to the Future" plays after "Heart of Chaos," during the clash of blades between Noel and Caius until before the final battle. In this track, the motif is rearranged alongside "Caius's Theme". In the "Closing Credits", "Paradox" plays after "Caius's Theme" and before "Noel's Theme".
"Paradigm Shift" plays in battles involving Serah during Arc 1 Chapter 9 and later.