Izzet Spellementals is almost entirely blue and red spells, making Flashfreeze extremely effective against Prismari Charm, Traumatic Critique, and their burn. Tishana's Tidebinder can counter Hearth Elemental's cost-reduction is not an ability to target, but it's still a flash 3/2 body that pressures their tempo plan and can strip an ability off Eddymurk Crab's ETB trigger. Settle the Wreckage is weak since they rarely attack with a wide board before you're under pressure, and Erode is a clunky answer to their small, replaceable creatures, so both are trimmed. Keep Spell Snare and No More Lies to fight through their cheap interaction and disruption suite.

UR Aggro is almost entirely red and blue spells and creatures, making Flashfreeze a premium answer to Burst Lightning, Ill-Timed Explosion, and their creature spells. Settle the Wreckage is risky since this deck can play around it or simply rebuild quickly with cheap spells, and it's trimmed in favor of a second Beza, the Bounding Spring, which stabilizes life total against their burn-heavy clock and blocks well as a 4/5. Get Lost gives them Map tokens that can fuel their explore synergies less relevantly here, so one copy comes out for the extra Flashfreeze. Day of Judgment and Erode remain vital to reset the board against their aggressive curve.

Dimir Midrange is light on wide creature boards, so Day of Judgment and Settle the Wreckage are weak sweepers against their planeswalkers, singleton threats, and card-advantage engines. Tishana's Tidebinder is superb, countering Kaito's loyalty abilities, Floodpits Drowner's stun-lock trigger, or Enduring Curiosity's death trigger. Rest in Peace stops Enduring Curiosity from returning after it dies. Keep the countermagic suite intact since this is a slower grindy matchup where No More Lies and Three Steps Ahead answer their bombs like Kaito and Elektra.