Feed the Swarm

For most of the game's history, mono-black carried a conspicuous blind spot: it could kill almost any creature, but enchantments sat outside its jurisdiction entirely. The color pie handed white and green the disenchants, and black paid for its reach into removal by staying blind to that half of the board. This spell patches the gap without violating the pie, and it does so by pricing the concession in the resource black spends most freely. The life loss scales to the target's mana value, so cracking a cheap aura or a small creature costs almost nothing, while reaching for a top-end enchantment or a fatty means opening a vein for it. That variable tax is the mechanism: black finally gets an answer it was never supposed to have, and it pays not in cards or restricted targeting but at the life counter. Notice the wording that keeps it fair beyond the life cost: it hits only permanents an opponent controls, so it can never be pointed at your own board for value, and it destroys rather than exiles, leaving recursion decks their graveyard intact. The design bargain here is unusually legible: black buys breadth of coverage and pays for it in the one currency it treats as expendable, spreading the cost across the size of whatever it needs to remove.