Mono-Blue Terror's entire maindeck is blue with no artifacts, making Pyroblast excellent: it counters Counterspell, Brainstorm, Thought Scour, Mental Note, or Tolarian Terror and Cryptic Serpent on the stack, or destroys a resolved Delver of Secrets. Keep artifact hate like Steel Sabotage-style effects out since the deck plays nothing for it to hit. Race aggressively before their mill-cantrip package assembles a cheap Tolarian Terror or Cryptic Serpent, since our clock is faster if unimpeded. Trim a couple of weaker standalone pieces for the proactive disruption Pyroblast provides against their permission suite.