Izzet Spellementals is another all red-and-blue spells deck, so Flashfreeze counters nearly everything they cast, from Burst Lightning to Prismari Charm to Slickshot Show-Off. We Say Thee Nay! and Spell Snare are too passive against a deck that wants to chain cheap cantrips and grow Eddymurk Crab or Hearth Elemental, so they come out. Ghost Vacuum lets you proactively exile threatening instants and sorceries from their graveyard before Eddymurk Crab's cost reduction gets out of hand, and can be sacrificed later to put exiled creatures onto the battlefield. Prioritize Floodpits Drowner on their early Eddymurk Crab and Requiting Hex on Slickshot Show-Off before they start compounding value.

Mono-Green Landfall's whole plan is cheap creatures like Llanowar Elves and Sazh's Chocobo compounding with land drops via Earthbender Ascension, so Day of Black Sun sweeping the low end of their curve is excellent. Flashfreeze counters almost every spell they cast. Spell Pierce, Spell Snare, and We Say Thee Nay! have weak targets against a creature-heavy, noncreature-light deck, so they come out for the sweepers and countermagic that actually answers their gameplan. Watch out for Icetill Explorer's extra land drops accelerating Ba Sing Se online faster than expected.

Jeskai Control has almost no early creatures worth your conditional removal, so Nowhere to Run, Shoot the Sheriff, and Spell Snare come out for proactive disruption. Duress strips Jeskai Revelation, Day of Judgment, or a counterspell before it matters, while Flashfreeze counters key red spells including Jeskai Revelation and Thor, God of Thunder. Disdainful Stroke answers their two big payoffs, Jeskai Revelation (mana value 7) and Thor, God of Thunder (mana value 5). Keep your own countermagic and Kaito, Bane of Nightmares as the primary win condition since this is a race to resolve a threat that sticks.