Dimir Midrange leans on fetchlands (Polluted Delta, Scalding Tarn, Bloodstained Mire) to fix mana and enable Psychic Frog/graveyard value, so Ashiok, Dream Render's static ability shuts off their fetch searches entirely, which is a huge tempo and disruption gain. Abrupt Decay is uncounterable removal that dodges their dense countermagic suite (Counterspell, Force of Negation, Spell Snare) and answers Psychic Frog or Tamiyo, Inquisitive Student cheaply. We cut Dredger's Insight and Formidable Speaker since they're clunky against a deck full of cheap interaction and discard (Thoughtseize, Fatal Push), and Strangleroot Geist trades down against their removal-heavy plan. Keep Orcish Bowmasters as a strong card since it punishes their card draw from Quantum Riddler and Tamiyo.