Mono-Blue Terror is entirely blue, making Pyroblast excellent — it can counter Counterspell, Brainstorm, Ponder, Tolarian Terror, or Cryptic Serpent, or destroy Delver of Secrets after it transforms. Hydroblast and Blue Elemental Blast have no red targets to hit so they stay boarded out, and artifact hate like Dust to Dust has nothing relevant to hit either. Dispel is downgraded since it only hits instants while Pyroblast is more flexible against this deck's mix of instants, sorceries, and permanents, so trim it for the Pyroblasts. Ethereal Haze is weak since this matchup is won through countering their threats and card advantage, not surviving combat damage.