Genius

A brilliant rogue, he pursues his career with élan, mocking the law for the sheer joy of it, rather than the sheer personal gain. He burgles because he finds it amusing, because he loves the sport of it. As H. Douglas Thompson states in his study, Masters of Mystery, "It is true that Lupin runs with the hare and hunts with the hounds, but it is impossible at times to know in what camp he is serving. Whether he is teaching the stupid but zealous prefecture its business or is, merely being a smiling damned villain."

Gentleman

Lupin is a Gentleman that only operates in the chateaux and salons, the one who entered the residence of Baron Shormann, but emerged empty handed, leaving his card on which he had scribbled the words, "Arsène Lupin, Gentleman Burglar, will return when the furniture is genuine."

Disguise	Arsène Lupin is a master of disguises. Leblanc created a man who could become in turn a chauffeur, detective, bookmaker, Russian physician, Spanish bullfighter, commercial traveler, robust youth or decrepit old man. Susan Dorff said that "Leblanc's tour-de-force . . made of the . . . whodunit a who-is-it." Even Lupin himself stated, "It is all the better if people are never able to say with certainty: 'That man is Arsène Lupin.' The great thing is that they should say without fear of being mistaken: 'That action was performed by Arsène Lupin.'"
The Ladies	Lupin, like many Frenchmen, has an undeniable passion for women. Indeed, his respect of the women give him a strong sympathetic connections for audiences: he restores certain stolen jewels to pretty women for little more than a beautiful smile that moved him. A charmer, he does not hesitate to pursue a beautiful face, even facing rejection or arrest for the sake of a woman. He is not an infallible seducer, which gives him a dimension more human than a number of other heroes of literature.

Sherlock Holmes and Arsène Lupin

Many feel that Leblanc has done for French literature exactly what Sir Arthur Conan Doyle has done for the English. Indeed, Arsène Lupin, Gentleman Burglar, has the intelligence and brilliance of Sherlock Holmes, but uses it for the other side of the law. He was the most familiar figure in French detective fiction and is France's greatest fictional criminal. Holmes and Lupin cross paths throughout Leblanc's work, though the Gentleman Thief only shows a certain mocking respect for the world’s greatest Consulting Detective.

Susan Dorff	H. Douglas Thompson	The First Story
An excellent article on French mysteries can be found here.	Masters of Mystery was published in 1931.	Uncredited material as quoted or paraphrased from Lupin's activities can almost all be found in "The Arrest of Arsène Lupin."