Izzet Spellementals relies on key synergies: Hearth Elemental's cost reduction from graveyard instants/sorceries, Eddymurk Crab's enter-the-battlefield tap effect, and Colorstorm Stallion's Opus trigger that grows it and can spawn copies. Torpor Orb is excellent here, shutting off Eddymurk Crab's tap ability. Authority of the Consuls makes their creatures enter tapped, further blunting their tempo plan. Ghost Vacuum picks off their graveyard to slow Hearth Elemental's cost reduction. Trim situational artifacts and reactive removal-adjacent pieces that are too slow against their cantrip-fueled speed.

UR Aggro is a fast, spell-triggered tempo deck, so Authority of the Consuls is excellent, both slowing their creature curve by making them enter tapped and gaining us life against a low-toughness swarm. Lodestone Needle and Pinnacle Starcage remain great against their cheap creature base. Cut slower, reactive cards like Dusk Rose Reliquary and Candy Trail that don't affect the board quickly enough against this aggressive clock.

Dimir Midrange is grindy with countermagic like Spell Pierce and Spell Snare plus removal like Bitter Triumph and Requiting Hex, so we want resilient, mana-efficient threats. Page, Loose Leaf gives us cheap artifact bodies that provide long-game card advantage via Grandeur, though watch for Requiting Hex. The extra Tezzeret, Cruel Captain is a strong grindy planeswalker against their removal-heavy shell. Ghost Vacuum lets us exile cards from graveyards and potentially reanimate opposing creatures later. Cut narrow anti-aggro tools like Lodestone Needle and Dusk Rose Reliquary that are weaker against a deck without cheap creature swarms.