Dimir Terror is another all-blue-and-black deck leaning on Counterspell and cheap cost-reduced threats like Tolarian Terror, so Red Elemental Blast is a great answer that can counter or destroy their blue spells and permanents for a single mana. Duress strips a Counterspell or Snuff Out before we commit our burn spells, clearing the way to close the game. Highway Robbery and Alms of the Vein are too slow and passive here, so they're cut for proactive disruption that directly attacks their blue-heavy game plan.