Mono-Black Midrange applies pressure with efficient threats like Hypnotic Specter and Nantuko Shade while disrupting your hand with Duress and Cabal Therapy, so you want cheap answers rather than card-disadvantage trades. Swords to Plowshares cleanly exiles Hypnotic Specter or Nantuko Shade before it grows out of hand, and Thrashing Wumpus can trade with or clear their small creatures like Ravenous Rats. Arcane Denial is a poor fit since handing them extra cards refuels their disruption, and Infernal Contract's life loss is risky against a deck packing Cursed Scroll and Hypnotic Specter damage. Keep your combo plan intact and use the swap purely for defense.