Nearly all of Mono Red Rally's spells are red (Gingerbrute is the main colorless exception), so Hydroblast and Blue Elemental Blast can counter or destroy key pieces like Burning-Tree Emissary, Clockwork Percussionist, Galvanic Blast, or Rally at the Hornburg itself, which is critical since that sorcery is their alpha-strike finisher. Trim Salt Road Packbeast, Leonardo, Big Brother, and Ornithopter for this cheap, efficient interaction since this matchup is a fast race where card quality per mana matters more than raw stats. Countering Rally at the Hornburg on the stack (with Blue Elemental Blast) is often the single best play available. Keep pressuring with our own artifact threats to force them to commit to the combo early, when it's most vulnerable to our blasts.