(Before I start, lemme tell ya: I LOVE THIS CHARACTER. Enough said, Btw, all of this is from the RWBY wikipedia, so I don't own! :)
Yang Xiao Long is a former student at Beacon Academy and one of the main protagonists of RWBY. Her weapons of choice are a pair of Dual Ranged Shot Gauntlets, Ember Celica.
She made her first appearance in the "Yellow" Trailer, searching for clues regarding the whereabouts of her mother, who left her when she was very young. At Beacon Academy, Yang becomes a member of Team RWBY alongside Weiss Schnee, Blake Belladonna and her younger half-sister, Ruby Rose.
Yang is a fair-skinned young girl with purple eyes and bright golden hair worn loose that fades to pale gold at the tips with a cowlick sticking out at the top. When she is angry, her eyes turn red.
She wears a tan jacket that bares her lower stomach, with golden brown piping and short, puffy sleeves with black cuffs that feature two gold buttons. Underneath this she wears a low cut yellow crop top with her emblem on the left breast in black.
She also wears a brown belt covered by a pleated brown piece of material reaching from hip to hip around the back of her waist, with her emblem emblazoned on the right-most pleat in gold. Underneath this is a longer, white, asymmetrical piece of material reaching to her knee on the right side, as well as a pair of black mini-shorts. She wears brown, knee-high boots and orange over-the-knee socks, with the right sock pushed down just below the knee. A lavender bandana is tied around her left knee. An orange infinity scarf and black fingerless gloves complete her outfit.
While riding her motorcycle, Bumblebee, she wears yellow goggles and a matching helmet that bears her emblem in black on either side. While outdoors, she sometimes wears a pair of yellow-rimmed aviator sunglasses.
Yang's voice actor, Barbara Dunkelman, has said that when Yang's character was described to her, she was described as "the kind of person who would teach someone how to swim by pushing them in the water". This speaks volumes about how Yang approaches most things in life. She is very straightforward and confident.
Yang is also described as being a cheerful, energetic and bright young lady. She is arguably the most flippant, carefree and adventurous member of her team, frequently making sarcastic comments and jokes even in the heat of battle and often taking combat and hostile situations lightly. Yang is very sociable and extroverted, even in unfamiliar situations.
However, Yang’s “brawler” fighting style is evocative of her personality. Her anger, one of her main assets in battle, can lead her to act predictably. When her hair is cut during battle, her resulting anger leads her to attacking with straight, blunt force. Additionally, a grudge against Neopolitan led to frustration on Yang's part, which quickly cost her the battle and almost her life. Her thoughtless anger led to the quick loss of her right arm in a short encounter with Adam Taurus.
Despite these things, Yang is deceptively mature. She is extremely nurturing, particularly toward her younger sister, Ruby. Yang pushes her into being outgoing and also worries a great deal for her sister across the many battles they fight in. This protective and encouraging nature extends to Blake and Weiss as well. Yang is worried for Blake on several occasions, such as when she runs from her team and when she suffers from sleep and appetite problems, opening Yang to discussing her stubborn past. What Yang doesn't reveal is that she suffers from abandonment issues, blaming herself for her mother not sticking around.
Yang’s love of adventure is a main reason she decided to become a Huntress. However, after the deaths of Pyrrha Nikos and Penny Polendina, the losses of her right arm and her partner, Blake, Yang sinks into a reclusive depression. The mention of her missing partner agitates her; she gives Ruby the cold shoulder and outright ignores her sister when she says, "I love you".
Over months, Yang rebounds from this reclusive nature. Though she experiences flashbacks, she tries to keep moving forward, partially for her father’s sake when feeling she holds him back. She accepts the wisdom of her father, Doctor Oobleck and Professor Port and dons her new robotic arm.
When training with her new limb, she learns how to balance her carefree nature without overconfidence or agitation. She paints her arm to match her style, changes to a new outfit and heads to Mistral, though Taiyang believes she has not overcome the personality that cost her arm.