Dimir Control's Counterspell and Dispel are the biggest obstacles to resolving our payoffs, so Duress proactively strips a counterspell before we commit to our key turn. Faerie Macabre is a flying threat/blocker against a deck with very few ways to interact with fliers, and discarding it can exile up to two target cards from a graveyard if needed for value. We shave Architects of Will and Repository Skaab since their card selection is too slow when the opponent already has Brainstorm and Lorien Revealed for their own card advantage — we need to be efficient and resolve threats through a small counterspell suite.