Jeskai Artifacts relies heavily on Urza's Saga, Mox Opal, and cheap artifacts fueling Goblin Engineer/Welder loops; Lavinia counters anything cast for free (Mox Opal-powered spells don't trigger this since they still pay costs, but her tax on noncreature spells over land count slows them down meaningfully) and generally disrupts their value engine. Surgical Extraction can strip a key piece like Emry, Lurker of the Loch or a combo artifact out of the graveyard to blunt recursion loops. Spell Pierce is weak since many of their key plays are 0-cost artifacts that dodge the tax, and Phelia is replaceable here since their deck isn't creature-heavy on defense. Keep Leyline Binding and Swords to Plowshares as flexible, cheap answers to their artifact creatures.