The EPIC Storm leans on Lion's Eye Diamond, Mox Opal, Chrome Mox, and Lotus Petal to fuel a storm kill, and Meltdown set for X=0 can blow out their free artifact mana sources before they go off. Pyroblast counters their blue Brainstorm or hits a resolved blue permanent, giving you cheap proactive disruption against their draw-smoothing. Spell Pierce is weak since they can often float enough mana from rituals to pay the tax, and Into the Flood Maw doesn't interact with their noncreature combo pieces. Prioritize disrupting their mana engine and forcing them off a turn, since racing their kill with Wasteland and Daze alone is often too slow.