Wrath of the Skies is a sweeper that can wipe their artifact-creature board (Emry, Sewer-veillance Cam, Pinnacle Emissary, Goblin Welder/Engineer) while sparing our own higher-cost permanents if we pay less energy. Disruptor Flute comes out of the maindeck plan since this matchup already has so many different low-cost artifact names (Lotus Petal, Mishra's Bauble, Mox Opal) that naming just one is low-impact. Keep Thalia, Guardian of Thraben and Wasteland in, since they tax their noncreature artifact spells and attack Urza's Saga before it can activate, respectively.