Mono-Black Midrange plays a disruption-heavy, creature-light game plan similar to your own deck, so the matchup is largely about card quality and resolving threats; Smother is fine here since Hypnotic Specter and Nantuko Shade both die to it, but you have more copies than needed given their modest creature count. Bring in extra Duress to fight their hand disruption on the draw and strip a removal spell or Cabal Therapy setup before they can use it against you. Pernicious Deed remains excellent since it answers Nantuko Shade, Mishra's Factory (when animated), and Cursed Scroll in one sweep. Keep the rest of the maindeck intact since this is largely a mirror-style grind decided by threats and disruption sequencing.