I don't know about this game Lightning Returns, so far it only shows her fighting.
Anyone play FF XIII-2? I heard that the battles involved only two people.
Not entierly ture. There are only the 2 main characters being Serah and Noel who can be any of the 6 roles but the 3ed party slot uses a monster pet system. When you defeat a monster it has a chance of dropping a crystal that you can use to include that moster in your party. You can have up to 3 in your paradigm set and they each only have 1 role. Instead of exp they use items that drop from battles to level up.
They become potent later in the game because while Noel and Serah have all 6 roles they only really excel as com and rav and are bad - average at the rest. Monsters however can be much more focused and you can feed them the crystals of other mosters allowing them to learn more abilities.
Edit: Monsters include everything from behemoths to chocobos
