Force of Vigor can blow up Urza's Saga before it finds an artifact, or destroy The Mycosynth Gardens is a land so it's not a legal target, but Amulet of Vigor is, cutting off their bounce-land combo acceleration for free on their turn. Subtlety has few good targets since their key pieces are mostly lands, enchantments, and sorceries like Scapeshift and Green Sun's Zenith rather than creature or planeswalker spells it can bounce. Force of Negation is excellent here, countering Scapeshift or Summoner's Pact to deny their combo turn. Keep the rest of the deck intact since this is primarily a race to resolve our own game plan before their Primeval Titan or Scapeshift lines come online.