"Lightning. It flashes bright, then fades away. It can't protect; it only destroys."

Lightning is a young woman with wavy rose colored hair, and pale aqua eyes. Lightning's eye color has been officially noted to be blue, though in the FMVs and promotional art they often appear green due to green aspects around the pupil. In Final Fantasy XIII-2 Fragments Before, Serah says Lightning resembles their mother.

In Final Fantasy XIII, she wears a variation of the standard Guardian Corps uniform. The green metallic pauldron over her left shoulder bearing yellow stripes denotes her previous rank as a sergeant. She carries her gunblade in a black case which hangs off her belt, and wears a necklace with a lightning bolt pendant. Her l'Cie brand is located slightly above her left breast. She has a navel piercing, although it can be difficult to spot.

Lightning FFXIII-2
In Final Fantasy XIII-2, Lightning wears a silver and gold Valkyrie-like suit of armor with a shield on her left arm (though in her CG render it appears on the right arm). She has a new gunblade more closely resembling a traditional doubled-edged sword, which has Etro script on it. She no longer has the navel piercing she did in Final Fantasy XIII.

During Lightning Returns: Final Fantasy XIII, Lightning has a number of different costumes. Her default outfit, Equilibrium, is similar to what she wore in Final Fantasy XIII-2. The Night Lotus shield on her left arm and the Crimson Blitz sword in her right hand, similar to Noel's Flame Fossil dual swords, are in homage to her Eidolon Odin. The game's logo appears on her outfit a number of times: on her chest, her sword and her shield.

Lightning is determined, concentrated and independent. Initially, she is cold and standoffish, distancing herself from her companions. She only looks out for herself and doesn't care if others are left behind. Much of her motivation is fueled from what she perceives as failing to protect Serah leading her to lash out at those she believes are responsible for that and her l'Cie fate: namely, the Sanctum, its fal'Cie and, to a point, Snow Villiers, due to his relationship with Serah and his failure to protect her as he promised. As she journeys with Hope Estheim and takes him under her wing, Lightning begins to show compassion and trust others, and sees the errors in her approach. Ultimately, she becomes the leader and, to a degree, protector of the other Pulse l'Cie as they journey to challenge their fate.

In Final Fantasy XIII-2, Lightning has almost become a new woman due to the experiences and emotions she has endured. She has learned to trust others and ask them for help, and expresses her emotions rather than keeping them bottled up inside her. Her time in Valhalla and recognition of her past "sins" has made her more somber.

Lightning - LRFFXIII
In Lightning Returns, Lightning is initially cold and distant, most of her emotions sapped from her, although her memories remain intact. Her wish to save Serah remains, and she still shows concern for her former allies. Lightning and Hope demonstrate trust and care for one another, Hope promising to be by her side, helping Lightning better maintain her humanity despite her situation. She resents Bhunivelze for robbing her of her emotions and his use of her situation to his advantage.

As her quest advances, Lightning begins to show compassion toward others because of her assigned task to save their souls. Straying from her cold-hearted personality, she begins to encourage those struggling implying Lightning unconsciously had given up her emotions, rather than Bhunivelze taking them with force, which is further suggested by Lumina. By the end of her quest, Lightning has come around from her self-imposed tough and emotionless warrior persona, as Serah and Lumina, along with all her experiences, help her realize that locking her heart away is how she threw away her happiness.