Meltdown for X=1 or X=2 wipes the bulk of Affinity's artifact base — Mox Opal, Claws of Gix, Welding Jar, Pithing Needle, Shadowspear, Engineered Explosives set low — but note that Kappa Cannoneer has a mana value of 6, so Meltdown cannot reach it at any practical X value. Unholy Heat with delirium (6 damage) kills Pinnacle Emissary and can catch an early Kappa Cannoneer if you pay its Ward {4} before counters grow it out of range, and even at base 2 damage answers the 1/1 Drone tokens Pinnacle Emissary spawns. Tormod's Crypt and Nihil Spellbomb deny Emry recursion from the graveyard. Cut some lands since Affinity's clock is fast and we don't want to flood while racing.