Mono-Blue Terror is almost entirely blue spells, making Red Elemental Blast excellent: it can counter Counterspell, Tolarian Terror, Cryptic Serpent, or any cantrip, or destroy a resolved Delver of Secrets or Tolarian Terror outright. Electrickery with overload deals 1 damage to each creature you don't control, which is enough to kill an unflipped Delver of Secrets (1/1) before it transforms. Vampire's Kiss and the extra Sazacap's Brew are cut since this matchup rewards proactive damage and answers to their threats rather than slow life-swing value, and graveyard hate like Nihil Spellbomb is skipped because it would only strip fuel from Tolarian Terror/Cryptic Serpent's cost reduction, which isn't a strong enough effect to warrant the slot here. Keep the aggressive burn plan intact and prioritize killing Delver and the Serpents before they get out of hand.