Hearthpwn

Hi, I've been playing this deck for a long time, mostly as a fun/troll deck. But recently I've tweaked the deck a bit and it's working great on ladder. I'm currently on rank 5, which I climbed from rank 8 with this deck. Unfortunately I don't have time to grind for legend this season as I can't play more than 4-5 games per day usually. This deck counters Grim Patron warrior and aggro decks pretty well. But it is weak against control warrior and freeze mage as the amount of damage you can do is limited. Handlock and Demonlocks are pretty even matchup and usually comes down to who draws better. If you can get a emperor with a couple of damage spells and velen you can win easily. 

Mulligan guide: Injured Blademaster + Circle of Healing / Nothshire Cleric + Velen's Chosen is always a keep with coin as well as without coin against slower decks.

Mage : Shadow Word: Pain for Doomsayer/Flamewaker, Acolyte of Pain aside from standard mulligan.

Warrior :  Shadow Word: Pain for Acolyte of Pain/ Frothing Berserker/ Armorsmith. Acolyte of Pain is great specially with a buff card. 

Rogue : Aside from standard mull you can also keep Injured Blademaster with Light of the Naaru if you got the coin. Acolyte of Pain is also great though it dies to Deadly Poison, most of the time it draws 2 cards. And it can kill their turn 3 tempoEarthen Ring Farseer/SI:7 Agent with Velen's Chosen

Hunter : Holy Smite, Deathlord, Northshire Cleric, Acolyte of Pain, Shadow Word: Pain. Stall the game by any means possible.

Shaman : Keep Holy Smite for the early Whirling Zap-o-matic as well as Shadow Word: Pain for early threats. Consider keepingAuchenai Soulpriest+ Circle of Healing for the board clear.

Warlock : It's pretty tricky since there are a lot of viable warlock archetypes. You want to keep Shadow Word: Death Against Handlock, Deathlord against zoo. Also keep in mind Auchenai Soulpriest+ double Circle of Healing can kill a board full of giants if things get out of hand.

Druid : keep Auchenai Soulpriest+ Circle of Healing to clear the Shade of Naxxramas

Priest : keep Acolyte of Pain of pain to punish his turn 1 Zombie Chow/Nothshire Cleric play. Deathlord+ Velen's Chosen is also good. I have a few games where opponent priest insta-forfeit after doing that combo since he can't deal with 4 attack creatures easily.

Paladin : Keep Holy Smite for early Knife Juggler, Deathlord(you're fucked if he kills it with equality and draws something big, but they don't usually mulligan for equality). Acolyte of Pain is also a keep, prevents him from playing Muster for Battle unless he have Knife Juggler on board.

 Card Explanation 

Circle of Healing : combo with Auchenai Soulpriest, Northshire Cleric, Injured Blademaster, Light of the Naaru

Holy Smite : One of your key combo pieces. Good against aggro too.

Light of the Naaru : Combo with Auchenai Soulpriest, Northshire Cleric, Injured Blademaster, Light of the Naaru. Also good against aggro where you can heal face for 3 and get a minion on board.

Power Word: Shield : Cheap cycle that lets you trade favourably and opens up more card draw opportunity for Northshire Cleric and Acolyte of Pain

Northshire Cleric : Card draw machine that is also efficient for stopping aggro.

Mind Blast : Main combo piece.

Resurrect :  combo with Injured Blademaster. Usually you want to use it a little late to revive Emperor Thaurissan. Double cost reduction is too good.

Shadow Word: Pain : Cheap removal for early threats.

Shadow Word: Death : Cheap removal for big threats.

Velen's Chosen : Buff card for spell damage and favourable trades.

Auchenai Soulpriest : Combo with Circle of Healing, Light of the Naaru and hero power.

Holy Nova : Board clear. Lets you draw cards with Northshire Cleric.

Prophet Velen : Key combo piece. Don't hesitate to heal face for 4 against aggro.

Acolyte of Pain : Card draw!

Deathlord : Aggro counter. Often buys you a turn or 2 against slower decks too.

Injured Blademaster : Early board presence and tempo. Lets you draw cards with Northshire Cleric.

Emperor Thaurissan: Discount to make combo cheaper.

Malygos : Spell power for 7 damage Holy Smite!