Izzet Tempo vs Lands

Null Rod is excellent here since it turns off Mox Diamond, Thespian's Stage copying activations, and other activated-ability-dependent pieces of their land-based engine, though it does not stop Life from the Loam's dredge or Exploration's static ability. Meltdown can answer their cheap artifacts like Mox Diamond and Expedition Map for a low X cost. Unholy Heat has few good targets against a near-creatureless deck, so it's cut. Wasteland remains important for attacking Urza's Saga and other utility lands before they combo off with Dark Depths and Thespian's Stage.