WUBG runs Sphere of Resistance to tax our spells and Oath of Druids as a threat engine; extra Seal of Cleansing gives us more ways to destroy either, which is crucial since Sphere of Resistance makes every one of our combo pieces harder to cast. Abeyance can stop a key instant response on our key turn, buying time to assemble Opalescence plus Parallax Wave. Mana Leak becomes much worse once Sphere of Resistance is in play since we're already taxed, and Intuition's card selection is less urgent than hard removal for their mana disruption. Watch for Wasteland and Rishadan Port pressuring our nonbasic-heavy manabase, and sequence Ancient Tomb carefully.