In Episode I it is stated that Sazh went off to be a pilot and brought his son along with him to evacuate the rest of the people on Cocoon. It does take place on pulse after a bit of civilization. Here is the official synopsis.
"Set a few years after Lightning and the others saved Cocoon, some survivors have decided to start over by rebuilding on Gran Pulse. Lightning, however, is nowhere to be found and thought dead by many, but Serah believes otherwise. When her town is suddenly overrun by monsters, a mysterious man named Noel appears to save her. Together, the two set off to find Lightning..." —Official Synopsis.
Ah so Noel uses multiple weapons?
"Set a few years after Lightning and the others saved Cocoon, some survivors have decided to start over by rebuilding on Gran Pulse. Lightning, however, is nowhere to be found and thought dead by many, but Serah believes otherwise. When her town is suddenly overrun by monsters, a mysterious man named Noel appears to save her. Together, the two set off to find Lightning..." —Official Synopsis.
Ah so Noel uses multiple weapons?
- Noel - A mysterious man who saves Serah from monsters. He accompanies Serah on her quest to find her sister. He uses multiple weapons ranging from a sword, two katanas, a bow, and a dagger.
- Serah Farron - Serah wishes to find her lost sister and sets out to search for her. Her weapon is a sword.