1BB
Instant
If it’s not your turn, you may exile a black card from your hand rather than pay this spell’s mana cost. Destroy all creatures that entered the battlefield this turn.
[MH1] Force of Despair
Obviously good against Vengevine, and potentially good against Token Makers+Shops+Dredge depending on their draws. I could see this having some impact.
Not as crazy as I was hoping the black one to be, but still a solid card for the sideboard I think. It's not too difficult to cast, and the main difficulty would be the black card density needed for the pitch cost.