This mirror-style control-midrange matchup rewards efficient countermagic; Mystical Dispute costs only {U} against their many blue spells (Counterspell, Preordain, Psychic Frog, Force of Negation, Subtlety) making it a cheap tax they often can't beat. Dovin's Veto is excellent since it cannot be countered by their own Counterspell or Force of Negation and answers key noncreature threats. Orim's Chant is weak against a deck full of instant-speed interaction that doesn't care about losing one turn of sorcery-speed plays, and Spell Snare is a lower priority than proactive card advantage in this grindy matchup. Keep Narset, Parter of Veils to shut off their card draw engines like Psychic Frog and Quantum Riddler, which is a premier threat here.