Against Dimir Control, Duress proactively strips Countersculpt, Spell Snare, or Deadly Cover-Up before they can protect their plan. It costs only {B} and, at mana value 1, dodges Spell Snare. Stinging Vitriol deals 2 damage and takes any nonland card, but at mana value 2 it is a Spell Snare target and costs two colors, so Duress is the better fit here. Gideon the Oathless is a 3/3 for three with ward—discard a card, and it punishes their plan: it deals 1 damage to them whenever a creature they control enters (including each Illusion token from The Theorist, Jace Beleren) and whenever they activate a loyalty ability. Requiting Hex (mana value 2 or less) can't kill it, and its ward makes Bitter Triumph cost them an extra card. Be careful with it against Deadly Cover-Up, which destroys all creatures, and Nowhere to Run, which ignores ward and gives -3/-3, so don't overcommit into a sweeper. Flamecache Gecko's ETB is weak here since the opponent rarely has lost life before it enters. Keep Burst Lightning as premium removal for Illusion tokens, Sphinx of False Conclusions, and pressure on The Theorist, Jace Beleren, and sequence around Countersculpt and Spell Snare.