Dimir Midrange's game plan revolves around Kaito and Enduring Curiosity card advantage plus disruption like We Say Thee Nay! and Tishana's Tidebinder. Duress proactively strips their noncreature, nonland cards, such as We Say Thee Nay!, Kaito, or their removal, before they resolve. It can't take creatures like Tishana's Tidebinder or Enduring Curiosity. Strategic Betrayal makes them exile a creature of their choice along with their graveyard. They pick which creature goes, so it's best when they have only one or two creatures out and has to be treated as edict-style removal, not a way to hit a specific threat. Erode is less valuable here since every kill hands them a free basic land, and Essence Channeler is a marginal body against a deck without much early aggression. Keep your core lifegain shell since it out-grinds their card advantage over a long game.