Eldrazi's whole plan runs through Chalice of the Void and various colorless/artifact support, so Force of Vigor can blow up two Chalice of the Void or other artifacts at once, and its alternative cost lets us answer a turn-one Chalice for free on their turn by exiling a green card from our hand. Disruptor Flute is live since it can tax their Thought-Knot Seer or Reality Smasher by naming them, make Kozilek's Command cost three more, or shut off Eye of Ugin's search ability (though not its cost reduction). Thoughtseize is weaker since this is a fast, proactive, low-interaction creature deck where a one-for-one discard spell trades down on tempo; Once Upon a Time is also less necessary since we want our interaction package live against their Chalice of the Void locking out our 0 or 1 mana value spells. Keep Collector Ouphe and Wasteland since both cut into their mana-artifact and land plans.