Grixis Affinity's Galvanic Blast is a red instant, giving Hydroblast live targets to counter or destroy, which also protects our creatures from their removal. Ancient Grudge destroys a nonland artifact like Myr Enforcer, Refurbished Familiar, or Ichor Wellspring, with flashback for a second kill; their Bridges (Drossforge, Mistvault, Silverbluff) are indestructible lands and immune to it, so target creatures or spellbombs instead. Moment's Peace only buys one turn against a deck that floods the board with cheap threats, so we trim it along with Lose Focus for more proactive answers.