Hearthpwn

I have had a go at this deck, using alterations from it on the Demon deck I already had. I crafted a golden Mal'ganis as soon as the expansion dropped because he's just so cool! :)

I've found that Sacrificial Pact is kind of a must have, no? The extra health from an Imp when you are Jaraxxus and low on health can be invaluable, as well as having the option to trigger your own Voidcallers when you want to and not risk them being silenced or drawing a new demon, and it's just so satisfying when a Priest steals your demons or becomes Jaraxxus, or someone Faceless Manipulator's Mal'ganis to save themselves and you always have that contingency plan for 0 cost. Does anyone else think this? Or am I way off here?

Also, the Lil' Exorcists, I tried them but did not find them to be very useful. Perhaps that's because I faced few deathrattle Hunters but they just seem to sit in my hand while I play out more appropriate cards?

A couple of other small things, like why only one Floating Watcher? And why two Shadowflames? How essential are cards like the Molten Giants, Sylvanas or Loatheb? I tend to find Flame Imps kind of important early game.

Sorry for the rambling, I am simply trying to get this deck sorted in my head so I know how it should actually be played, rather than just throwing out cards. :)

EDIT: Mortal Coils, too! So useful to keep card advantage and help keep the board clear until you can get out a good Mistress or something, no? Why are they not utilized?

Lil' Exorcist - I feel bites me in the rear a lot. I swapped it with Shadow Bolt

I know there are a tun of DR cards now. But turn 3 I feel better if I got a bolt in my hand.

I personally dont like sacrificial pact, most of the times is a dead card, I see sacrificial pact a good card in tournaments but not on the ladder.

Lil'Exorcists is a great card, good drop for 3 mana and if you are facing a Undertaker oriented deck it's gg! Trust me, lil'Exorcist has a great value!

One floating watcher is more than enough, you will find that if floating doesnt come via voidcaller he is kinda bad, so 1 is more than enough. Why 2 shadowflames? Well you have moltens + sylvannas + voidcallers. With moltens you can wipe all monsters on the enemy field, with sylvanna you can wipe almost everything and if you dont kill everything you still control what's left, and shadow flame + void caller is a strong aoe removal plus you put a free demon on the battlefield, that's why I have 2 shadowflames, the combos you can do are just insane!

In the early version of this deck I had flame imps instead of moltens, it's true that flame imps early game are just awesome, but late game most of the time you cant play it (cause you are low health) or they are just a dead card, and moltens are just awesome, low health? np, let me just put 2 8/8 in the same turn with low mana cost! Trust me molten > flame imp (I tried myself). 

Mortal coil is a good card, no doubt about that, but you can't really trade mortal coils for anything on the deck, all cards are important and have a role, not saying mortal coil is bad, but there are cards with more value than them, and you dont need to care about card advantage, you are a warlock! ^^

Hope I helped! Thanks and gl!

This is the only card that will make me run 2 blood imps in a deck. If you manage to play both blood imps they will with time buff each other a bit while buffing other minions, when you play this card the imps should be strong enough to survive most AOE's and then you have a 9/9 on board ofc. Buffing the imps with something else is an other option, or maybe play an other stealth minion.