Devoted Combo wants to resolve Green Sun's Zenith or Nature's Rhythm to tutor a combo piece and go off with Devoted Druid plus Vizier of Remedies for infinite mana. Mystical Dispute is live against their blue-adjacent spells only rarely, but mainly comes in for the generic counter mode at full cost to stop their key tutors and combo enablers; keep in mind it is only cheap against blue spells, which this deck rarely casts. Ashiok, Dream Render stops their Green Sun's Zenith and other library searches from finding what they need and can mill away their Agatha's Soul Cauldron targets over time. Day's Undoing is dangerous to fire off against a deck that can rebuild a fast combo from a fresh seven, and Sink into Stupor is too slow against a deck planning to go infinite before you can leverage its land side.