Dimir Control is full of blue cards (Counterspell, Spellstutter Sprite, Faerie Seer, Augur of Bolas, Ninja of the Deep Hours, and the blue-black Baleful Strix), so Red Elemental Blast and Pyroblast come in. They counter a Counterspell or Spellstutter Sprite at the key moment, or destroy a blue permanent such as a Sprite, Seer, Augur, Ninja, or Strix. Smash to Smithereens is a marginal addition. It can destroy a Baleful Strix, or a Mukotai Ambusher, which is also an artifact, while dealing 3 to the opponent's face, which matters when racing a control deck that wants to stabilize. The core burn-and-discard engine should stay largely intact, since this matchup is about resolving threats under their permission suite (Counterspell, Spellstutter Sprite, Dispel) and racing before Thorn of the Black Rose and card draw spells grind us out. Cut the slowest card-advantage pieces to keep the curve low and the clock fast.