So affected by Azkaban, Rabastan's pride in his appearance has slowly degenerated, resulting in his condition going from neat to unkempt. A very different person from the young, handsome man sentenced to life in Azkaban, Rabastan is a fairly tall, thin, gaunt character with a pallid complexion and a straight, narrow nose. Shaggy, medium-brown hair that is in desperate need of a cut covers his ears and forehead, nearly hiding a pair of deep-set (and, to pull a cliché, haunted) hazel brown eyes. His face is drawn, and lined with fatigue; the contours of his face disrupted by the occasional pockmark and the permanent stubble that no amount of persuasion can make him get rid of. Since Azkaban, he has been susceptible to cold; in fact, he is seldom seen without a thick jacket or scarf.
A sharp-tongued, charming and cynical man with a teenage arrogance and immaturity he has never been able to grow out of (and probably never will), Rabastan is self-conscious and competitive; constantly arguing with his brother (and most other people). Seen by most as a childish, petty person, only those who are close to him are aware of a kind of multiplicity he possesses within his head. Prone to complaining, whining and annoying behaviour, he is a very hard person to tolerate, especially for those who deal with him on a day-to-day basis; his words and actions can often land him in trouble. He rarely thinks of the consequences his actions may have, and is very impulsive.
The flip side of his personality – far from the glib, loudmouthed younger brother he seems to be – is usually only seen in situations of dire circumstance, or, when he does in fact get off his lazy arse, situations of 'business'. In these cases, he can be coldhearted, sadistic and altogether ruthless. When he does present this side of his personality, it is usually a surprise, as most know him as the annoyance he usually is.
He possesses an explosive temper when pressed, holds grudges, and the use of any means to get what he wants is not beyond him. He does not remain very calm in situations of great pressure, and a nervous tic – he runs his fingers up and down the bridge of his nose – tends to convey his real feelings than anything he says. He craves the praise of his peers and in this sense he can be a devoted and conscientious worker, if it weren't for the fact that until he is pushed, he won't work.
Acceptance and the fight for sanctity of Pure Blood are his only motivations – otherwise, he is simply an idle man content to sleep, eat and vegetate. Since Azkaban, he has developed a very strong dislike towards Dementors, as their presence seems to take an immense toll on his mind and body.
Rabastan is the youngest of two brothers from a near-fanatic pureblood family that preached the preservation of their pureblood line to their sons (and most other people). Younger brother to Rodolphus, and brother-in-law to Bellatrix, Rabastan desperately clings onto his older brother in an attempt to gain some kind of approval from a family member, albeit in a supremely childish and argumentative way.
His time at Hogwarts – he was sorted into Slytherin, naturally – was a constant competition with Rodolphus. Though an able wizard in his own right, Rabastan simply did not have the attention span nor the respect for authority required to be a good student at Hogwarts and thusly, was not very popular amongst his teachers. He excelled at Transfiguration and Defense Against the Dark Arts, was fairly capable at Potions, Arithmancy and Charms, but, despite tutoring in the field, he performed dismally at Herbology and Divination, citing them to be a complete and utter waste of time.
Upon leaving Hogwarts, Rabastan travelled to Paris with a group of schoolmates, one of whom was Narcissa Black. During the time spent there (most of which was spent drinking away portions of trust funds), the pair had a clandestine relationship. When the group returned to England, they went their separate ways – until Rabastan received an invitation to Narcissa Black and Lucius Malfoy's wedding.
After leaving Paris, Rabastan learned that his brother had joined the Death Eaters and hurriedly followed suit. Before he was Marked, his demonstration of childish behaviour often earned him punishment from his superiors however, after his initiation, a ruthlessness and utter disregard for human life seemed to surface within him and enabled him to rise up through the ranks to become one of Voldemort's most trusted Death Eaters, despite being reprimanded occasionally for demonstrating behaviour unbecoming of a servant of the Dark Lord.