Dimir Midrange is loaded with blue spells like Counterspell, Preordain, Quantum Riddler, and their own Consign to Memory, making Mystical Dispute a premium answer that can often be cast for just {U}. An additional Consign to Memory helps counter key triggered abilities like Orcish Bowmasters and Psychic Frog's damage trigger, or colorless spells they might bring in like Nihil Spellbomb or Engineered Explosives. Lightning Bolt struggles to profitably trade since threats like Psychic Frog can grow to dodge 3 damage, and Prismatic Ending is less necessary against a deck with few problematic permanents early, so both are trimmed. Keep your Leyline Bindings and Stubborn Denials in as Leyline Binding answers Tamiyo, Inquisitive Student and both remain strong against Kaito, Bane of Nightmares.