A deck that is more evil than this is hard to get. If you meet a player that has been playing since the early days, chances are the mono black deck is the deck they have the most vivid memory of. This deck plays all of the good black creatures paired with format power house Underworld Dreams to attack the enemy on two angles.
One card the mono black player seldom leave home without is the black boon, Dark Ritual, a card which allows for classic plays like a turn one Hypnotic Specter or turn two Juzam Djinn. Budget versions of this deck usually trades the crazy expensive Juzams for Su-Chi which also allows them to play City in a Bottle in the sideboard. Another card worth mentioning is Sinkhole, a card that sometimes can win games by itself.