Moonstone, Harsh Mistress

Discard has always been the color's cost, the resource you spend and forget. Here the resource loops back. Every discard, whether it comes from a rummaging effect, a cost you paid, or your own end-step overflow, opens a window: exile the card and cast it before your following turn closes. That timing is the important part. The card does not return to hand and it does not sit in the graveyard for reanimation math; it becomes a play, on a clock, at whatever speed the card itself allows. An instant discarded to a loot can come back at instant speed; a land pitched because your hand flooded can simply get replayed. The effect turns discard from a downside into a delayed draw, which reframes how you evaluate every card-filtering effect around it. The 2/4 with flying reads modestly for its cost, and the body is built to defend rather than pressure: the four toughness lets it survive an unfavorable block or eat a small attacker, and the evasion keeps it relevant on offense against opponents without their own fliers. It is a creature that asks only to stick around long enough for the discard trigger to fire again and again. What keeps it from spiraling is the exile clause doubling as a leash: you get one shot at each discarded card, and only within a narrow window, so the engine rewards a deck already generating discards rather than one straining to manufacture them.