Lightning is determined, concentrated, and independent. She's initially cold and detached, distancing herself from her companions, only looking out for herself, and not caring if others get left behind. Lightning's perception of failing to protect Serah drives her, leading her to lash out at those she believes are responsible for her fate: the Sanctum, its fal'Cie, and to a point, Snow Villiers, for his relationship with Serah and his failure to protect her as he promised.