Dimir Excruciator is a control-oriented deck full of removal (Bitter Triumph, Theorix Charm, Requiting Hex) and card advantage (Superior Spider-Man, Seasoned Cryomancer), so proactive hand disruption is key to protecting your development. Duress takes away their Duress, Requiting Hex, or Bitter Triumph before it can answer your threats. Strategic Betrayal is a clean permanent answer to Superior Spider-Man or Overlord of the Balemurk while also denying their graveyard recursion plans. Deadly Precision's extra cost is a liability against a deck already attacking your resources, and Callous Inspector's 1/1 body underperforms against their bigger bodies like Seasoned Cryomancer.