Grixis Affinity floods the board with artifact creatures like Myr Enforcer, Refurbished Familiar, and Utrom Monitor and closes with burn and sacrifice effects. Thraben Charm's damage mode (twice our creature count) can kill their small threats like Refurbished Familiar (a 2/1) and Krark-Clan Shaman, which is the card that most threatens our 1/1 hexproof creatures because it doesn't target. Its enchantment-destruction mode has only one target in their deck, Makeshift Munitions, but it is still useful flexibility. Faerie Macabre costs no mana to use: discard it to exile up to two cards from graveyards. Its best use is in response to Blood Fountain's activation, exiling the creature cards it would return, and it also blunts any graveyard-based plan. Exiling Ichor Wellspring after it dies does nothing, since its card draw has already happened. Cut the slower Cartouche of Solidarity and two Silhana Ledgewalker, whose evasion is weaker against their flyers (Refurbished Familiar and Utrom Monitor), since this matchup is a fast race where interaction matters more than incremental value. Our hexproof creatures can't be targeted by Galvanic Blast or Cast Down, so their real answers are sweepers like Krark-Clan Shaman and edict effects, which is why cheap interaction against those creatures is worth the slots.