Gluttony: Horace Slughorn
Horace Slughorn was a men of refined taste; he liked superb whiskeys, excellent company, delicious food, and, above all, incomparable connections. This was always present in the character of the Potions Professor, however it wasn't until he arrive to Slytherin that he learned how to take advantage of it.
Slughorn wasn't an important name in the Magic World, it wasn't uncommon, but the purity of the caste was diluted so it didn't cause the same impact as before. Even Horace mother was a half-blood, which is why when Horace entered the Slytherin Common Room didn't cause the same impact as a Black or a Rosier, even though he didn't cause a bad impression.
During his first years at Hogwarts, Horace preoccupied himself to stand out to the Professors, trying every school activity, club, and everything that he could make to get on the good side of the people in power. By his third year he was invited a couple of times to the Malfoy Manor, and to join the Black for the festivities; making him realize that he had the capacity to attract people; and adopting a new way of living: "You get more flies with honey than vinegar".
Horace learned to use his charisma, and filled his vocabulary with compliments and praises; but above all he learn to know his limitations. Slughorn understood that the world wouldn't stop for a person of limited capacities and a long forgotten name; that's why, the future Professor, worked hard on identifying other's talent.
Everything started on his fifth year, when he "pondered" on his seven-year classmates; first on the Common Room, then on the Great Hall, and last on study sessions. With the "I need help studying" excuse, Horace, manage to befriend the most influential group of seven year Hogwarts students, which lead to invites to "exclusive" events.
A couple of years later Horace was in his seventh year, and his graduated friends made a name for themselves in the Magic World.
Horace knew that after Hogwarts he would have a tedious future, and his work wouldn't be spectacular or promising. It was true that he was good in many areas: Transfiguration, Potions, Charms; but he didn't stand out in either of them. At first he got a job on an office that transported magic artefacts; the pay was good, the hours weren't long, and he had time to visit if "important friends", however; with time; that didn't cut it for Horace. He wanted more.
He tried to do the same search of talent between his clients, important people in the Magic World. But his boss didn't allow him such liberties. Eventually his "friends" move on, that's why when Hogwarts' Headmaster offered him the Potion's spot he accepted immediately.
By his first year Slughorn already had a small collection of 12 students in which he saw some potential. Children of former classmates, of people he didn't knew, and so on. The first ones to graduate under his wings were grateful about his words of encouragement and great disposition in class, that's why after they left Hogwarts they kept inviting him to share with their friends and family.
Slughorn went back to the good life, and no one questioned for long his magic precedence, and always with great company. Even so this little achievements never gave him satisfaction.
For his fourth year at Hogwarts, Slughorn organize a little gathering once a month where they shared dinner and gave him a chance to really studied his future collections.
At some point the Potions Professor understood that compliments would be enough to get people, that's when he started to do favours. Some extra points to the Houses, making someone into the Slytherin Quidditch Team, asking some old friends for work interviews for the new ones. That's how the shelves in his office everyday had more pictures of his conquers, and less of his own family.
Quidditch Players, Prophet's Reporters, Aurors, Ministers of Magic, people in charge of the import of Magical Creatures; anyone that could pay a favour in the future would decorate the shelves and walls of Professor Slughorn's office; making the new students marvel in awe, and his ego burst every time he explained the relationship between him and those people.
But Slug wasn't dumb, he knew that after he collected his favour, or someone more important and less common entered the lives of those influential people, those who he called "friends" would forget him completely. That's why he needed more pieces for his collection, to fill every spot of his office with pictures and trophies of connections that told the world that Slughorn contributed to change the Magic World through his collection.
Horace wasn't satisfied with three Ministers of Magic, or more than a complete Quidditch Team of the Professional League, neither singers nor actresses manage to fulfil the Professor, he needed more and more. More influence, more dinners, more bottles of fine whiskey, more favours, more "I wouldn't done it without you, Professor", more and more.
Everyone would think that when Horace Slughorn, Head of the Slytherin House, meet Tom Marvolo Riddle, his hunger for power would seize to exist, however not even the Darkest Wizard of the time made Slughorn stop collecting.