This is a race where their madness engine (Fiery Temper discarded off Faithless Looting) plus Kessig Flamebreather and Guttersnipe can out-damage us if the game goes long, so we want to lower our curve's reliance on the all-in alpha strike and add resilience. Relic of Progenitus exiles their Sneaky Snackers before a third draw brings them back tapped, denying free blockers/attackers, and doubles as graveyard hate against any Faithless Looting flashback value. Smash to Smithereens is a 2-for-1 that kills a Blood token or other artifact while dealing 3 to the face, directly contesting their damage race. Pyroblast and Red Elemental Blast stay in the board since the only blue targets this opponent presents are Sneaky Snacker and the occasional gifted Fish token, which is too narrow to justify a slot. Trim Goblin Bushwhacker copies since all-in alpha strikes are riskier against a deck that can race through combat tricks and reach lethal first; keep the core Rally/artifact engine intact.
Dimir Control has no red cards, but most of its deck is blue: Counterspell, Spellstutter Sprite, Faerie Seer, Augur of Bolas, Ninja of the Deep Hours, Brainstorm, Lorien Revealed, Dispel, Plunder the Trollshaws, and the blue-black Baleful Strix. That makes Pyroblast and Red Elemental Blast live in this matchup. They can counter a blue spell such as Counterspell in response to our Rally at the Hornburg, or destroy a blue permanent such as Baleful Strix, Spellstutter Sprite, Faerie Seer, or Ninja of the Deep Hours. Bring in all three Pyroblasts and the Red Elemental Blast, and take out the Goblin Bushwhackers. Bushwhacker's kicker wants extra mana, and a 1/1 body does little against Strix's deathtouch and their cheap removal. Their only artifacts are the artifact creatures Baleful Strix and Mukotai Ambusher, so Cast into the Fire's exile-artifact mode and Smash to Smithereens can hit them, but those cards are narrow and stay in the sideboard. Tectonic Hazard and End the Festivities each deal 1 damage to every creature they control, which kills Baleful Strix, Spellstutter Sprite, and Faerie Seer. They are sorceries that Counterspell can answer, so we leave them out to keep the deck fast. Our plan is to race before Counterspell, Snuff Out, and the monarch from Thorn of the Black Rose take over. Hold a blast to protect a key Rally or burn spell from a counter, and use it on a Strix or Sprite when they tap out.
Spy Combo wants to ramp into Balustrade Spy mill triggers and Dread Return reanimation, and fields a lot of small-toughness blockers like Wall of Roots (0/5 is safe, but Elves of Deep Shadow, Quirion Ranger, and Mesmeric Fiend are all 1-toughness) to stall while they assemble their engine. Tectonic Hazard and End the Festivities' 1 damage to all their creatures punishes that wall of small mana dorks and chump blockers while also chipping their life total directly. We trim Goblin Bushwhacker since they have enough early blockers (Overgrown Battlement, Wall of Roots, Gatecreeper Vine) that an all-in haste turn can be chumped repeatedly; a steady burn-to-the-face clock closes the game before their ramp payoffs come online. Keep Galvanic Blast and Lightning Bolt as flexible removal/reach.
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