Debilitating Injury

A -2/-2 aura is a sharper instrument than it looks because it answers two kinds of threats with one card. Against the bottom of the curve it functions as removal: anything with toughness two or less dies the moment it resolves, with no damage-prevention dodge and no indestructible loophole to climb over. Against the larger bodies it cannot kill outright, it leaves them shrunken and easier to wall, race, or trade with. The clause that defines it is permanence: where a combat trick fades at end of turn, the -2/-2 rides along with the Aura, so a creature it failed to kill stays diminished across future turns and slips out of relevant combat math. That same stickiness is the lever an opponent uses against it. Bounce or flicker the enchanted creature in response and the debuff is shed, sending the Aura to the graveyard, though that is a clean one-for-one: their spell answers yours, card for card. As an Aura it must target while on the stack, so hexproof and shroud lock it out, and protection from black both stops it from targeting and peels it off a creature it is already attached to. Inside those guardrails black is wagering that the cheaper price and the absence of a destruction or exile clause to play around buys back the lower ceiling. It is the all-purpose shrink effect black has returned to in many forms, trading the certainty of destruction for a lower cost and a wider net of legal targets.