Deadly Tempest

The wrath you can win with. Black has been destroying all creatures since the earliest sweepers, but the plain version of that effect leaves a hole: you clear the table to slow an aggressor down, and the aggressor, now even on board, rebuilds from a life total you never touched. The card-advantage math of a Wrath of God favors whoever was behind on creatures, but the life-total math is a wash, and that is the gap this closes. Bolting symmetrical life loss onto the destruction means every creature in the wipe charges its controller a point. The player who flooded the board with a dozen tokens loses a dozen life when they all die at once; the player holding two creatures pays two. It is symmetrical in name, but it lands asymmetrically because the boards are rarely the same size, and the deck casting this is built to keep its own count low. Note that the life loss reads only off creatures destroyed this way: indestructible bodies, anything that dodges destruction, and anything already gone contribute zero, so the payment scales precisely to the carnage you actually inflict. The six-mana price is the tax for stapling that reach onto a board wipe, which turns a reset button into something closer to a finisher. Most sweepers buy you a turn to survive; this one can take the last chunk of life off a board-flooded opponent on the same cast.