Eldrazi's Chalice of the Void is the single biggest threat to our plan, locking out an entire mana value for the rest of the game; Force of Vigor destroys up to two artifacts for free (by exiling a green card from hand on their turn) and can blow out a Chalice of the Void before it locks us out, or hit a second one plus a stray artifact. Cabal Therapy is weak since their hand is full of creatures they intend to play, not hold, so we cut two copies along with the slower Destroy the Evidence and Memory's Journey. Keep all fast mana and Pact of Negation, since beating a Chalice set at 0 means going off before they untap, or using Force of Vigor to clear it first.