Grixis Affinity wins by flooding the board with zero-cost threats before you can establish your aura engine, so your priority is disrupting their artifact base while protecting your heroic creatures from Galvanic Blast. Fragmentize and Revoke Existence come in to permanently answer key artifacts like Ichor Wellspring and Refurbished Familiar — Revoke Existence in particular exiles rather than destroys, which matters against Blood Fountain recursion. Standard Bearer is excellent here because it redirects Galvanic Blast away from your suited-up heroic creatures, forcing Affinity to spend removal on a vanilla 1/1 instead of your Akroan Skyguard or Lagonna-Band Trailblazer. Spirit Link and Lifelink come out since they provide life gain that is largely irrelevant against a deck that aims to kill you with large attackers rather than burn, and Skyward Spider is too slow against their aggressive curve. Focus on getting an Ethereal Armor or Cartouche of Solidarity onto a creature early and use Benevolent Blessing to protect it from Galvanic Blast if Standard Bearer isn't in play.