So this wouldn't be usable if there's only one minion on your opponent's field right?
By th time you use this card (at least 6 w/o coin) to remove your opponent's minions, you're likely to have other cards that are very valuable later on, such as a Mal'ganis, Jaraxxus, or other legendaries so I'm not sure if discarding 2 cards is fair.
so I can laugh at you later on when it turns out that it isn't a thing at all.
I'm not saying you'll put a whole bunch of discard into your deck just for the luls, I'm saying that a Warlock zoo list will be able to pull off Fist of Jaraxxus with Dark Bargain and Doomguard. Like Dragon Warrior pre-TGT, you're just running a bit of the stuff because it's good, not because you want your entire deck to revolve around a single mechanic.