Ping decided at a very young age to reject the system of the wulin, recognizing no laws other than the ones she would choose for herself. Normally this would lead to a life of delinquency and imprisonment but she defied the odds and has grown up into an inspirational example of teenage rebellion. Although she has no desire of becoming a leader of war (mindlessly copying Ping's rules for yourself would be missing the point) it is nevertheless very convenient that the Black Crane school helps her get the things she wants.
In a recent tournament she obtained the right to study the forbidden Black Crane Scrolls which greatly increased her power. She is without a doubt the most powerful warrior of her generation. Nobody knows just what kind of plans she has, thanks to a rare bloodline that makes her "invisible" to predictions and abilities that rely on supernaturally augmented observation.
Also known as the Baneful Crane, the Wayward Blossom, Ping the Merciless, Power in the South, and the Black Queen.
http://www.youtube.com/watch?v=Hj2vU2nr5Jw. Theme song: Disturbed - Indestructible
The Buddhist Diamond Mantra is part of an unorthodox sect that views the wulin as a world of endless cycles of violence and revenge. As such, she has come to see Ping as a potential saint who one day can break that world and usher in an era of peace.
Sheguai is the living prison for a monster, although whether that's metaphorical or literal is hard to say. What is clear though is that normally she is a friendly and warm person but she can also experience sudden changes that increase her internal power and let her harm enemies with a mere glance.
Her name literally translates as "strange snake" or "freaky serpent". Her school mates often call her Guai Guai, which is a pun that gets lost in translation. (It means something like "weird-weird" but is pronounced almost the exact same way somebody would call a good obedient child or cute pet.)