Wilt in the Heat

Five damage at instant speed with exile-on-death is already a premium removal profile: it clears nearly any body, denies death-triggers their payoff, and slams the door on recursion by removing the corpse from the yard entirely. The interesting part is the discount, and it works backward from how graveyard-matters cards usually pay. Delve, escape, and flashback all bill you for a graveyard resource: they consume cards sitting in the yard. This one asks for graveyard departure, specifically that one or more cards left your graveyard this turn, whether by an escape spell, a reanimation, a shuffle-back, or any effect that empties your bin. The graveyard stops being a stockpile and becomes a switch: it does nothing full, and everything the moment a card vacates it. Cast dry, it is a four-mana instant. Fired on the turn your recursion shell goes off, it drops to two, though the timing binds it: the discount lives only during the turn a card actually left the yard, so it rewards proactive removal on your own turn rather than a cheap answer held for the opponent's.

Built as a Boros self-recursion payoff, the discount becomes nearly automatic once escape and reanimation pieces are online. What tethers the rate is not the exile clause (that is strict upside) but the single-target, reactive shape: even at two mana it buys the removal of exactly one thing, never a board. And damage does not touch indestructible creatures; they survive the five, never die, and the replacement effect never fires.