Demonic Torment

Fun fact: Legends' original subtitle was "A bunch of miscolored white cards."

Cards inspired by Demonic Torment:

etc., etc.

Black can punish combat with auras, too, but it's not going to blanket rule that "You can't do this, you can't do that"; black's all about pulling people's strings and punishing them for acting against it. See:

Not that Mortal Wound's actually good, of course. Why no -X/-X auras? Simple -- I don't like them. They're sorcery speed, so they're hard to be tricky with; if they don't outright kill your target, the loss of flexibility and the possibility of enchantment removal means they're almost always worse than the sorcery or instant equivalent; and they're generally too small (often in the -2/-2 range) to get a cost discount. Quag Sickness is the only one I can think of that gets a discount -- about half a mana off -- from equivalent removal spells (Tendrils of Corruption and its ilk), but for removal that costs more than two mana, I'd still generally take Tendrils of Corruption because of the instant speed and life gain.

The key to the black attack-impeding enchantment isn't in bluntly stopping the attacks; that's white's bailiwick. Black doesn't really give a whit about the sanctity of life, and is far more likely to just blast the offending creature into dust -- or to use it as a pawn to further its own gameplan. (That's another reason why white gets to imprison opponents -- it often has moral or ethical objections to certain kinds of killing.) Black auras represent long-term investments -- they're supposed to stick around for a while -- so they should reflect black's power broker, devil's choice side. In other words, they should punish the enchanted creature -- or its controller or owner -- for acting a certain way.