Hydroblast is dead against Mono-Black Midrange since they run no red spells or permanents, so it should not be boarded in. Essence Flare is very effective here, placing -0/-1 counters on Hypnotic Specter or Nantuko Shade over time to destroy them while your countermagic disrupts Dark Ritual starts. Prioritize protecting your hand against Duress and Cabal Therapy by playing around discard when possible, and use Stifle proactively on activated abilities like Nantuko Shade pumps or Mishra's Factory. Trim reactive spells that are weak against their disruption-heavy plan for more proactive threats and answers.