Squall has long blonde hair, red eyes with a mole under her left eye, a beautiful face, voluptuous body and a large bust that been described as very attractive by both Ran and Ichika.
Her arm and her right eye are artificial. She lost them in an accident of maneuverability when she was in the US Army.
Squall shares a homosexual relationship with Autumn. She usually displays herself as mature, polite, level-headed and ladylike in front of others, be they be friend or foe. While she can be very ruthless when she want to be and doesn't mind using force, she did order M not to kill the soldiers at the American base. Suggesting that either she doesn't like needless overdoing thing when it's unnecessary or perhaps she has some other reason.
While Squall is the leader of one of Phantom Task's squads, she does have a good side to her. Compared to the cold Madoka and aggressive Autumn, Squall is willing to help someone in need because she feels satisfied from doing so, even if there's nothing gained from it. She also cares about her comrades and will go save them if she needs to.
Infinite Stratos & Abilities
As the leader of a Phantom Task squad, Squall is a highly trained and dangerous fighter. She has incredible reflexes, being able to deploy her IS and subdues M with it when she tried to attack her with own IS. Squall has enough confidence in her IS and her skills with it that she believed she could match Tatenashi Sarashiki, the strongest student in the IS Academy and the IS Representative of Russia, something she later proved. In fact, she would have beaten Tatenashi if Kanzashi hadn't arrived in time with the Haute Couture packages for the Mysterious Lady.
Squall also has a lot of connections. She was able to invite Tabane Shinonono, someone who has been able to avoid all the countries of the world, to an underground restaurant. She is mostly likely a capable strategist given her position and the number of IS her squad has. She is also a skilled negotiator, having managed to convinced Alicia Jiosestaf into joining Phantom Task so she could get her rematch with Chifuyu.
Being a cyborg, Squall's artificial limbs are likely stronger and more durable than normal limbs. She can also replace them if their destroyed, allowing her to uses them as shields if she has to. As a downside however, it's harder for her to recover from injuries.
Squall pilots the Golden Dawn IS, a third-generation that possess both strong offense and defense capabilities.
Squall was once a member of the US special forces. 12 years before the story timeline, she was said to be KIA. However, she survived and was turned into a cyborg. At some point, she joined Phantom Task and eventually became the squad leader of Monochrome Avatar direct action cell.
During the CannonBall Fast, Squall accidentally bumps into Ran Gotanda. She is later shown commenting on M's abilities to hold off all six personal IS users effortlessly, before getting into a skirmish with Tatenashi Sarashiki. She is shown to be skilled enough to hold off Tatenashi with partial deployment and block all her bullets with a yellow cocoon-like shield. She confidently tells Tatenashi that the Mysterious Lady would not break through her IS but chooses to escape from the Academy instead.
After M's attack on Ichika, she talks to her about maintaining her identity and about her getting revenge on Chifuyu Orimura. A few days later when Ichika goes to a high-class restaurant for a dinner with Houki, Squall shows up and helps Ichika by buying him a suit to enter the restaurant. When he leave, she introduces herself to him while saying his name (confusing him since he never introduce himself).
Thus unknown mean, Squall manages to invite Tabane Shinonono to dinner. Squall request that Tabane make IS's with cores for Phantom Task, which Tabane refused. When Squall try to force Tabane to agree (in the LN Autumn held Choloe Chronicle hostage and in the anime Autumn pointed a gun at her head), Tabane easily overpowered the two. M tries intervene but Tabane just disable her IS. Everyone became shock to see that Tabane knew M was Madoka Orimura and further that she was willing to make her a new IS but had to come with her.
Squall: "Hey, M. Whether you're Orimura Madoka or not, I don't really care, but please maintain your identity as M while being a member of Phantom Task."
Madoka: "...I intend to do so until I settle the score."
Squall: "Settle the score...with Orimura Ichika?"
Madoka: "Humph...he's not a threat at all. I can kill him whenever I want to."
Squall: "So that means, with Orimura Chifuyu...right? - Orimura Chifuyu, is it? She doesn't have an IS, so I don't think she's much of a threat."
Madoka: "Don't you ever humiliate her...Someone like you will never be a match for nee-san..."
Squall: "Okay okay, I got it. So M', don't throw the knife. You'll damage the wallpaper."
Squall: "I'll go sleep for a while. Ah, M? There's still some time until the next mission, so please control yourself a bit."
Madoka: "Got it."
Squall: "I like honest kids. Bye then, M." - Squall to Madoka 
- ↑ LN Vol 9 Ch 4
- ↑ LN Vol 9 Epilogue
- ↑ Vol 9 Ch. 4
- ↑ Vol 10 Ch. 4
- ↑ LN Volume 9 Ch 4
- ↑ LN Volume 9 Epilogue
- ↑ LN Volume 7 Ch 1