Stalwart Valkyrie

Nobody plays this Angel for its printed rate; a 3/2 flyer at four mana is a body you tolerate, not one you build toward. The whole design lives in the alternative cost: and a creature exiled from your graveyard, which drops the same flyer to two mana once the bin is stocked. That reframes the card as a self-mill or sacrifice payoff, converting a creature you were already finished with into aerial pressure at a discount the mana cost never advertises. The exile clause is what keeps the trade honest: this is not recursion, it eats the fuel rather than returning it, so it competes directly with reanimation and flashback-style effects for the same graveyard bodies. You are spending a dead card for a rate reduction, not manufacturing something from nothing. The discount is flat and indifferent to what you exile: any corpse pays the same freight, which makes the yard a fuel tank rather than a toolbox you pick from. Cast it fair when the graveyard is empty, cheat it down when you have overflow. It rewards decks whose creatures die early and often, and does nothing in decks that never fill the bin.