Mainboard (60)
Creatures (12)
Instants (14)
Sorceries (8)
Artifacts (8)
Boros Energy has a wide array of threats at every mana cost — Guide of Souls, Ragavan, and Ocelot Pride at one, Ajani and Phlage at higher points. The sideboard Unholy Heat copies upgrade your removal suite to deal six damage with delirium active, cleanly answering Phlage, Titan of Fire's Fury which dodges your mainboard bolts. Mystical Dispute counters their key noncreature spells like Seasoned Pyromancer and counters their sideboard Orim's Chants. Surgical Extraction removes Goblin Bombardment or Ocelot Pride from the game entirely. Spell Snare and Spell Pierce are limited in a matchup where your goal is to be the beatdown and their threats curve from one to four mana.
Jeskai Blink wins through Solitude, Phelia's blink engine, and Consign to Memory shutting down your spells; you need to bring your full countermagic suite to compete on that axis. Consign to Memory counters their Solitude, Phelia, and Quantum Riddler at instant speed — it's their primary removal and threat. Mystical Dispute is efficient counterspell protection for your creatures and disrupts their blue interaction. Spell Snare counters Ephemerate and Prismatic Ending at one mana. Meltdown, End the Festivities, and Surgical Extraction are not impactful against a fair creature deck; Mutagenic Growth and some pump spells are cut to improve your spell interaction density.
Affinity's board is dominated by artifacts — Mox Opal, Urza's Saga constructs, Kappa Cannoneer, and Pinnacle Emissary. Meltdown destroys all their cheap artifacts at a massive one-mana discount, sweeping Mox Opal, Mishra's Bauble, and any zero-cost artifacts in one blow. Unholy Heat with delirium deals six damage, cleanly answering Kappa Cannoneer and Pinnacle Emissary that would otherwise require multiple spells. Spell Snare counters their two-mana answers like Metallic Rebuke and Engineered Explosives. End the Festivities and Violent Urge don't interact with artifacts; Spell Pierce is weak against a deck that plays around countermagic easily.