Mono-Black Midrange runs entirely black cards, so Compost triggers constantly off their own Duress, Cabal Therapy, Dark Ritual, and dying creatures, generating a steady stream of extra cards over a long game. Xantid Swarm, free through Aluren, lets us attack and shut off their disruption or removal on our combo turn, which matters against a deck built to strip our hand with Duress and Cabal Therapy. Cut Bone Shredder and Mesmeric Fiend since we already have ample card advantage and disruption coming in, two Wall of Roots since this matchup is more about card quality than mana, and Sylvan Library since its life payments are risky against a deck with Hypnotic Specter and Nantuko Shade applying pressure.