Blue-black is related to secrets and forbidden knowledge. Blue's emphasis on information and black's solitary nature combine to create a very secretive color pair. The opponents of Blue-Black decks often realize that they are going to lose when it is too late.

Common mechanics: Milling, card draw, discard, library manipulation, casting from graveyard, large creatures with big drawbacks, unblockability

Common creature types: Merfolk, Faeries, Rogues, Assassins, Wizards

Ravnica guild: House Dimir