Flowstone Flood

The buyback experiment Exodus ran through a hostile filter: instead of paying extra mana to return the spell to hand, you bleed three life and discard a card at random. That second clause is the genuinely interesting design choice. Random discard is rare in any color, and stapling it to a recurring effect means every replay is a gamble on your own hand: you might pitch a land, you might pitch your bomb. The card asks whether repeatable land destruction is worth surrendering control of what you keep. Most buyback spells of the era let you pay a premium and otherwise play normally; this one builds the cost out of resources you cannot fully choose, which caps how oppressively you can chain it even when you have the life to spare. The base spell is plain single-target land destruction at four mana, a rate that was never going to make waves on its own. The buyback is the whole pitch, and the designers clearly understood that a freely recurring "destroy target land" would be miserable, so they priced the recursion in attrition you cannot direct. It is a study in how to make a repeatable effect legal: not by raising the mana, but by making the player surrender a random card from hand every time they reach for it, so the engine slowly cannibalizes the deck it is meant to protect.