Voidfire Wand is really good, but isn't broken. And really, it has the same overall effect as Greench, except you have to deal damage with it. Equipment hate, armor, a protector - there's a lot of ways to stop it from hitting you. Solo Warrior can be really good against that deck, because any armor can stop Voidfire, Puncture can kill Voidfire, and as long as you play around it, Bringer of Death isn't a big deal. Just don't over commit. Bloodrage can wreck them, because while they're busy spending one card to make you discard one, you can just reload your hand, and play out a couple weapons to keep some pressure on them. If they blow up everything with the Bringer, you can just play Bloodrage to reload. Playing Bringer of Death before turn 8 is risky for them, since you run 4x Puncture, and should save them against them.

A lot of their cards are useless - Doshura loses his effect; Melt Face and Soul Rend can't do anything.

And you can side a lot of stuff against them as well - Wreck, Felsteel Reaper, etc. 

"I play Bringer of Death. Your turn". "I play Felsteel Reaper, attack you for 8. Go" "I play Bringer of Death AGAIN" "I play another Felsteel Reaper, and hit you for 9 this time. Are you dead yet?"

Couple corrections, actually, because I messed this up with Tatulla elsewhere. There's a difference between making your hero untargetable and abilities and powers that target your hero. Basically, Melt Face, Tatulla, and Soul Rend all target the player so the Terror Pit Girdle is, unfortunately, less useful in this situation than I had originally anticipated.

That being said, in my neverending quest to redeem myself against Tatulla mess-ups, Blessing of Freedom is actually a valid counter to hate cards like Tatulla, because the Blessing is ongoing that is destroyed only at the EOT step. So opponent plays Tatualla, players plays Blessing in response, player sacks Blessing once Tatulla resolves into play.

My first thought against Voidfire discard involves finding ways to make your hero untargetable. Armor might help against Touch of Darkness and Mind Spike, but it can be targeted and destroyed just as easily. This makes me think Paladin and Blessing of Freedom or rogues (gnome rogues even) with Cloak of Shadows. Mages can also Fizzle discard spells and Nether Fracture the Voidfire Wand.

The problem then, of course, is priest's typically running a lot more discard than you could run counters and interrupts. Maybe Rogue then might be the better answer to this priest discard with a turn 3 Pilfer.

Against the version that won DMF Stuttgart, Terror Pit Girdle would pratically auto-win you the game. All but two of its hate/discard cards rely on targeting your hero. All they could hope to do is side in the two Nyn'jahs game 2 or 3 and hope they can draw it in time.

Anyway, just some thoughts. I've yet to really test any of this just thought I'd throw you some musings.