Esper Control is a tap-out and hard-counter control deck built around Teferi, Time Raveler, Orim's Chant, and Counterspell to lock opponents out, then winning with Teferi, Hero of Dominaria or Solitude beats. Mystical Dispute is one of the most efficient tools in this matchup, countering Teferi, Time Raveler, Counterspell, and Consign to Memory for a single blue mana — critical since Teferi at three lets them play at sorcery speed and cripples your flash-based game plan. Consign to Memory answers Isochron Scepter (which they can bring in with Orim's Chant imprinted), their own Consign to Memory, and key permanents without being countered by regular Counterspell. Your Harbinger of the Seas is particularly punishing here, as Esper relies on Hallowed Fountain, Flooded Strand, and Misty Rainforest to color-fix across three colors. Endurance, Collector Ouphe, and Boseiju have minimal impact against their spell-heavy plan, so they make room for the counter package.