Essence Flare can help contain Nantuko Shade or Hypnotic Specter by eventually shrinking them down with its recurring -0/-1 counters, though it takes a few turns to matter so it's best against their grindier threats rather than an immediate Dark Ritual-fueled Hypnotic Specter. This deck has no red or artifact/enchantment spells worth countering with your other sideboard cards, so those stay boarded out. Your counterspell suite (Counterspell, Foil, Daze) is already well-positioned to protect your Dreadnought from Smother, Diabolic Edict, and Chainer's Edict, so keep that core intact. Watch for Duress and Cabal Therapy stripping your hand before you can deploy the combo, and try to hold up protection rather than overextending into open black mana.