You may play the exiled cards until the end of your next turn
Swamp #B04 (RNA Ravinca Weekend) by Jenn Ravenna This is the territory of the Orzhov, the guild of business comprised of an ostentatious hierarchy of priests, enforcers, and ghostly councilors that rule over a congregation of guilt-bound loyalists and indebted ghosts
Does this mean that you just have to get lucky and pack the cards you need
5 Kappa Cannoneer An Artifact Menace Enters The Modern Battlefield Kappa Cannoneer was the genesis for a powerful Legacy deck colloquially referred to as "8-Cast," a strategy that looks to put a slew of cheap artifacts into play to reduce the cost of cards with the affinity mechanic or to sit on the battlefield and be tapped for improvise
(You may cast cards from your graveyard for their escape cost.) If The Master of Keys is no longer on the battlefield when its second ability resolves, you'll still mill twice X cards
So long as you can protect them, if your opponents care about cards entering the battlefield and dying, your opponents theme can be completely nullified, leaving them helpless
