Survival Elves relies on Survival of the Fittest to dig for answers and threats, and Phyrexian Furnace lets you exile cards from their graveyard, disrupting Squee, Goblin Nabob recursion and Genesis-style value engines from their sideboard. Plaguebearer gives you a way to destroy small mana creatures like Birds of Paradise and Llanowar Elves, slowing their Gaea's Cradle plan. Diabolic Edict is weak since they have many expendable creatures to sacrifice instead of a real threat. Discard their Survival of the Fittest or Armageddon with Duress and Cabal Therapy as early as possible, since Armageddon into Gaea's Cradle can run away with the game if you fall behind on board.