Elves floods the board with small mana dorks like Llanowar Elves and Fyndhorn Elves before going over the top with Craterhoof Behemoth or Natural Order into Atraxa, so Firespout cast for {R} deals 3 damage to each non-flying creature and wipes their entire mana base of dorks in one shot, since none of them have more than 1 toughness. Barrowgoyf also blocks profitably against their small creatures with deathtouch while growing into a real threat. Sink into Stupor only answers a single permanent against a deck that goes wide fast, and the extra Giant's Boulder is too slow to matter before they assemble Gaea's Cradle mana. Watch for Collector Ouphe shutting off Grim Monolith and Expedition Map's activated abilities.