This is a grindy attrition matchup between two blue-black tempo-control strategies, but Dimir Terror has a key structural advantage: Mental Note and Thought Scour let them fill the graveyard rapidly, enabling near-free Tolarian Terrors as early as turn two. Bojuka Bog and Relic of Progenitus come in to tax that graveyard fuel, forcing their Tolarian Terrors to cost significantly more mana and slowing their Gurmag Angler development. The Monarch through Thorn of the Black Rose is the central resource battle — they're likely siding in their own copies, so having a second Thorn to reclaim it after trades is valuable. Mob Lookout's life gain and 1/2 body are irrelevant in a matchup defined by large flyers and counterspell wars, and Spell Pierce loses value as the game goes long and both players have excess mana. Prioritize holding up Counterspell and Snuff Out on their key turns rather than developing proactively.