Esper Control is full of blue spells (Teferi, Narset, Day's Undoing, Sink into Stupor) making Mystical Dispute a cheap, efficient counter, while Consign to Memory snipes their colorless and triggered-ability threats for a single mana. Ashiok, Dream Render shuts off their fetchland shuffles tied to Day's Undoing recursion and can proactively mill/exile their graveyard to deny Solitude evoke recursion or flashback plays. Force of Negation is less needed since we're bringing in cheaper, more targeted counterspells, and Faithful Mending is too slow against a deck that will out-grind us on card advantage with Day's Undoing and Teferi locking our interaction to sorcery speed. Prismatic Ending comes out since many of their key permanents (planeswalkers at 3-4 mana, Narset) cost more than we can typically converge colors to exile efficiently early, and removal is less valuable than disruption against a control shell.