Cassius Grey

Cassius Leon Grey (b. 1 August, 1952) was a pure-blood dark wizard and Death Eater. He, like fellow Unspeakable Augustus Rookwood, was a spy in the Department of Mysteries. His cover as a spy was not blown until after the war, in which his wife, Matilda, discovered his connections to Voldemort. In retaliation, Cassius murdered her in cold blood and went on the run, eventually being tracked down and sent to Azkaban. He would later escape in 1996, serving his master as a Death Eater once more, and taking part in several battles throughout the Second Wizarding War. He was present on the 2 May, 1998 during the Battle of Hogwarts. He was killed there by his son, Simon, and future daughter-in-law Audrey.

Early Life
Cassius Leon Grey was

The Battle of Hogwarts

 * "Did you expect some revelation? There is none. I loved your mother - once. Perhaps... perhaps I still do... But this cause is about something greater! A better world, a purer world, for our children. Can't you see that? You're on the wrong side, son. The Dark Lord doesn't want such precious blood to be spilt. He has use and appreciation for talents such as yours."
 * ―Cassius, to his son Simon during their final duel.

During the Battle of Hogwarts on 2 May, 1998, Cassius was one of the Death Eater combatants assaulting the castle. He was seen casting Fiendfyre at a group of younger students that stayed and was confronted by some of the ghosts of the castle who had come to the students' defense. During the battle's brief intermission, he was seen by the Forbidden Forest. When the battle resumed, he was again spotted in the castle, assaulting various students. He was stopped this time by Simon and Audrey, who engaged him in a vicious duel. He had the upper hand for a time, being a seasoned wizard and remorseless killer, blasting Audrey aside with the Expulso Curse, and began to torture his son, with the intent to eventually kill him. Audrey recovered and retaliated in time, destroying and killing Cassius with the Blasting Curse.

Physical Appearance
Cassius looked a great deal like his son, Simon, with fair skin, dark features, and a prominent aquiline nose. He was considered by many to be handsome, which helped him keep up his cover as someone who was loyal to the Ministry. He had dark hair that he wore down to his shoulders and had neatly trimemd sideburns and stubble.

After his outing as a follower of Lord Voldemort and his incarceration in Azkaban, Cassius' hair grew longer and had a greasy appearance. He let his stubble grow into a salt-and-pepper beard. His eyes lost any of their previous charm, replaced with a corpse-like malice instead. He had the Dark Mark tattooed onto his left inner forearm.

Cassius always wore black or dark clothing. During his time as a Death Eater, he wore the customary robes, along with a mask. His mask was a burnished bronze in colour and had a gleeful expression.

Personality and traits

 * "What sort of man abandons his son, betrays his friends, and murders his wife?"
 * ―Audrey Galland.

On the surface, Cassius seemed a man like any other: caring towards friends and family, proud of his work, and an upstanding citizen who believed in and followed wizarding law. Once, perhaps, this was true. But what lay underneath the surface was in stark contrast to the charming persona Cassius adopted. He was a stark proponent of blood purity, looking down upon those who were not "pure of blood." He regarded half-bloods with midling contempt - but tolerated them. He utterly despised Muggle-borns and Squibs, considering them "blemishes" that "needed to be pruned."

As a younger man, Cassius was charming and gregarious, easily making friends with others. From a young age, he was taught that pure-bloods were superior to others and so cultivated friendships with others who were "pure". While he regarded those who weren't pure-blooded as "others", he refrained from tormenting, mocking, or bullying them as other Slytherins were wont to do. He had a thirst for knowledge and a malicious cunning that enabled him to play rivals and enemies against each other. Perhaps not surprisingly, Cassius cultivated a secret interest in the Dark Arts.

After falling in with Lord Voldemort and his followers, Cassius maintained the veneer of civility towards others. What lay beneath, however, was a man of fanatical belief, unwavering loyalty, and brutal cunning. Unlike other Death Eaters, he was not overly sadistic, instead preferring to eliminate or kill his opposition outright rather than toy with or torture them. He prized efficiency over all and looked upon many of his compatriots with slight disdain, considering them brutes. He profusely hated the Ministry for "enabling" Muggles. Such was his loyalty and fanaticism that when confronted by his own son years later, Cassius showed no signs of remorse nor had any intention to surrender or repent.

Possessions

 * Wand: Cassius received his wand from Ollivanders wand shop when he was a young boy. It was made from blackthorn wood, with a core of dragon heartstring. It had a vaguely hooked shape. Mr. Ollivander described it as "contentious."

Lord Voldemort
Cassius was very loyal to his master, willing to sacrifice his career in the Department of Mysteries and his family in order to follow him.

Death Eaters
Cassius openly associated with Augustus Rookwood, both during their Ministry years and as Death Eaters, considering Rookwood a friend. He also openly associated with Lucius Malfoy, being friends since their time at Hogwarts. He was respectful towards many others, but considered Bellatrix Lestrange too unhinged and dangerous. Cassius resented the likes of Thorfinn Rowle and Crabbe, considering them "mindless barbarians."

Etymology
Cassius is a Latin name. It means "hollow", but also "narcissistic" and "vain." Leon is a given name and surname that both mean "lion." Grey is a colour between black and white. Grey is often associated with boredom, old age, secrecy, and uncertainty.

Behind the scenes

 * Cassius' zodiac sign was that of Scorpio.
 * If given Amortentia, Cassius would've smelled violets, incense smoke, and burning wood.
 * Had he not fallen in with Lord Voldemort and the Death Eaters, Cassius would've remained an Unspeakable and would've even opposed the dark lord during the First and Second Wizarding Wars.