Dimir Terror fills its graveyard with Mental Note and Thought Scour to cast Gurmag Angler and Tolarian Terror for one or two mana, so disrupting that engine is critical — Faerie Macabre can be discarded from hand for free to exile graveyard cards, slowing their delve threats without costing you a turn of development. Guardian of the Guildpact is your most important threat in this matchup because it dodges their entire removal suite: Cast Down, Snuff Out, and Abandon Attachments cannot target it due to its protection from monocolored. Your primary game plan is to land a Guardian of the Guildpact and resolve Armadillo Cloak on it, creating a lifelinking threat they have almost no clean answer to. Sacred Cat comes out because it dies to Suffocating Fumes and is a low-impact play against a deck that can go over it with 5/5 delve creatures. Hold up Prismatic Strands to protect your board through their combat steps and be cautious of Counterspell and Spell Pierce when tapping out for key spells.