Grixis Affinity floods the board with cheap artifacts to power out Myr Enforcer and Refurbished Familiar via affinity, and Pillage can destroy non-indestructible pieces like Ichor Wellspring, Seat of the Synod, or Vault of Whispers to slow that plan (note the Bridge lands are indestructible and immune). Hydroblast counters or destroys their red spells and permanents, most notably Galvanic Blast, which can hit for 4 with metalcraft online. Trim slower cards like Campfire, Pulse of Murasa, and Unfathomable Truths for this proactive artifact disruption. Prioritize Counterspell on Myr Enforcer or Refurbished Familiar before affinity makes them nearly free.