Izzet Affinity is an artifact-combo deck that wins by generating massive card advantage and board presence through Urza's Saga constructs, Kappa Cannoneer, and Emry recursion loops. Force of Vigor is your premier answer — it destroys Mox Opal, Urza's Saga, and Seat of the Synod at instant speed, dismantling their mana engine before they can go off. Collector Ouphe is a silver bullet you can fetch with Green Sun's Zenith that shuts off all their artifact mana and activated abilities, buying you the time needed to assemble a Natural Order or Craterhoof kill. Snuff Out handles Kappa Cannoneer and Emry efficiently without requiring mana, which matters when you need to hold up interaction while developing your board. Their Force of Will and Sink into Stupor tax your key spells, so prioritize landing Thoughtseize early to strip countermagic before you commit to a Natural Order.