Null Rod is devastating here, shutting off Mox Opal's metalcraft mana ability, Chrome Mox, Lotus Petal, Seat of the Synod, and the sacrifice abilities of Mishra's Bauble, Urza's Bauble, and Tormod's Crypt, crippling their artifact mana base and cantrip engine. Thorn of Amethyst further taxes their Thoughtcast and other noncreature spells. Our own Chalice of the Void mirrors theirs and can be set at zero to blank Mishra's Bauble, Urza's Bauble, and Lotus Petal while they can't easily play around it with their low curve. Sire of Seven Deaths and some It That Heralds the End copies come out as too slow against this proactive combo-aggro deck.