Hearthpwn

will see some experimental play as a tempo card but otherwise i don't think it's going to stick around.
it's just a bad Dragoncaller Alanna.
aggro is literally everywhere and requires you to clear the board almost every turn if you want to survive past turn 4.
so since everyone is running at least 3 board clears to have a chance climbing past rank 15, i don't see a world where this card can be good. it will die to any decent board clear: Frost Nova + Doomsayer, Hagatha the Witch + Lightning Storm, Vanish, Deathstalker Rexxar + Unleash the Hounds. Oh, and it's also completely useless against Warlocks and Twisting Nether. And not to mention the amount of resources you have to spend on that thing for it to be barely playable. so yeah, unless you Keleseth, double Soul Infusion and can play a 2 mana Loatheb -which is not in Standard- it will be an "8 mana do nothing" type of card just like Void Contract. oh and that Spirit of the Bat fantasy where you have Hir'eek, the Bat and trade your whole board to buff the thing ? that's not happening either. we all know how 1/2/3 mana stealth demons have worked in the past. they just don't.

This is not an anti-control card. As you said, there's a lot of aggro on ladder, and this card can be decent in tempo match-ups. Games can go a long way trading back and forth. Honestly I think in a Zoo mirror, even with only Keleseth's buff, playing seven 2/2 is really good, and if you get an Infusion on it and play seven 3/3 it's game over.

I'm not saying it's a good card, I just want to point out that it can be a decent late-game play in aggro mirror. And you can have enough mana to play the legendary spell that draws 3 (sorry forgot the name I don't really play Zoo) + this one in the same turn (unlike Gul'dan which is I guess why Gul'dan is not really played in Zoo anymore).

Hir'eek, the Bat plus Evolve from Witch's Cauldron. easy seven 9-Mana minions. only wild though :/

Oh, you can have warlock cards with a Shaman in Wild now ?? Well that's some cool news

he means warlock plays witch's cauldron which is classless card and warlock would get evolve from witch's cauldron.

Seems like a cool card, right now Warlock only really has Spirit of the Bat and Soul Infusion to use on this.
Maybe we will see some more cards this expansion that will have synergy with this card.

um Violet Wurm is a common 8 mana 7/7 neutral beast with a death-rattle that fills your board with 1/1s so wtf is this crap? looks like a legendary placeholder.

This can potentially be 7 8/8s. WAY better imo.

It was shown as really cool combo with new spirit card on BlizzCon HS panel and might be a way for zoo-ish locks to win late game after baiting all clears. Adding more strategy to one of the most tragic decks ever might be good but let's hope not too good.

dream