Paradox

Paradox (パラドクス) is the term used for an anomaly in the spacetime continnum that causes the strange events in Final Fantasy XIII-2.

Datalog
''Following the appearance of the gate that appeared in New Bodhum in 3 AF, Time Gates began showing up in a multitude of locations. The research institute, the Academy, gave a name to the anomalies that accompany the arrival of these gates and cause impossible things to happen--they called them 'paradoxes.'''

In any location where a paradox is present, people report strange occurrences, such as the sudden appearances of unusual monsters, and odd connections to other times and places.

Music
The paradox concept has its own eponymous theme, titled "Paradox," composed by Naoshi Mizuta. Variants of this theme are "Miracle of the Battle," "Paradigm Shift," "Brand of Vows," "The Ruler of Space and Time," and the "Ending Credits."