Grixis Affinity floods the board with cheap artifact creatures like Myr Enforcer and Refurbished Familiar while Galvanic Blast threatens to hit for 4 with metalcraft, so Suplex's artifact-exile mode is excellent at removing a key artifact (like an Ichor Wellspring or a Bridge land) to slow their affinity cost reduction, while its damage mode can also kill their small creatures outright. Nylea's Disciple gains solid life off our green devotion to offset their burn and aggressive artifact creatures. We trim our slower, more vulnerable cards since this matchup rewards being proactive and disrupting their artifact synergies before they overwhelm us on board.