Dimir Midrange is grindy with discard, removal, and card advantage engines like Narset, Parter of Veils and Consult the Star Charts; your own Narset shuts off extra draws from sources like Cryogen Relic while digging you to answers. Spell Snare is excellent against their glut of mana value 2 spells (Consult the Star Charts, Nowhere to Run, Cryogen Relic, Momentum Breaker, Sheoldred's Edict), though it can't hit their one-drops like Boomerang Basics or Hopeless Nightmare. Dovin's Veto can't be countered and protects your threats from their noncreature removal while also answering their Narset. Temporary Lockdown is trimmed because it can't touch Narset (mana value 3) and mostly hits cheap permanents you can handle more efficiently with counters; March and Erode are trimmed since their creature count is low and more proactive answers are preferable here.