Which Final Fantasy game stars Lightning as its main protagonist?

The Final Fantasy game starring Lightning as its main protagonist is Final Fantasy XIII.

Lightning, whose real name is Claire Farron, is a former soldier living on Cocoon, an artificial world threatened by conflict between Cocoon and Gran Pulse. When her younger sister Serah is branded a l’Cie, Lightning becomes determined to rescue her, drawing her into the game’s central struggle against the fal’Cie and the fate imposed on their human servants.

Final Fantasy XIII has six playable characters, but Lightning is its central protagonist and the character most closely associated with the story. She returns in Final Fantasy XIII-2 as a major supporting figure and becomes the sole playable character of Lightning Returns: Final Fantasy XIII. Her distinctive pink hair, gunblade, serious personality, and military background make her easy to identify, although she is sometimes confused with other prominent heroines such as Terra, Yuna, or Rinoa.