Hydroblast and Blue Elemental Blast are premium here, countering or destroying red spells and permanents like Kessig Flamebreather and Guttersnipe outright. Nihil Spellbomb strips the graveyard to shut off Fiery Temper's flashback-adjacent recursion window and slows Faithless Looting's card selection, though it does nothing to stop madness casting since discarded madness cards go to exile, not the graveyard. Abandon Attachments and the clunkier creature-based cards come out since this matchup is a race decided by cheap interaction, not big bodies. Prioritize tempo: countering or blasting Guttersnipe and Kessig Flamebreather on sight denies their damage engine before it snowballs.

Hydroblast is the premier upgrade: it counters any red spell (Fiery Temper, Lightning Bolt, Lava Dart) or destroys any red permanent (Kessig Flamebreather, Guttersnipe, Voldaren Epicure) for one mana, directly shutting down their damage engine. Abandon Attachments is too slow and card-disadvantage-neutral against a deck racing to kill you by turn 5-6. Suffocating Fumes only grants -1/-1, which fails to kill Kessig Flamebreather (1/3) or Guttersnipe (2/2) and is not worth a slot here. Keep all removal (Snuff Out, Cast Down, Agony Warp) and counterspells online since answering their engine pieces before they trigger is the win condition; Snuff Out is especially strong since you'll usually control a Swamp-producing land and can pay 4 life to kill Guttersnipe or Kessig Flamebreather at instant speed.

Steel Sabotage and Annul are dead here since Mono-Blue Terror has no artifact or enchantment spells to hit, and Hydroblast/Blue Elemental Blast have no red targets, so none of those come in. Extract a Confession forces a sacrifice of their best threat, hitting an unprotected Tolarian Terror or Cryptic Serpent since Ward only stops targeted effects. Arms of Hadar's -2/-2 doesn't kill Tolarian Terror or Cryptic Serpent but cleanly answers Delver of Secrets and any Bird Illusion tokens. This is a mirror-ish matchup of counterspells and card selection, so keep the full Counterspell and Dispel suite and just add a bit more proactive removal to punish their threats.