Hearthpwn

The minute I saw Spirit Echo during the Un'goro prerelease, I knew I wanted to make this deck.  The idea is very simple: mill your opponent like a Rogue.  Except, instead of using Shadowstep and Gang Up, you're relying on Youthful Brewmaster and Spirit Echo.

This deck has struggled to work because there just wasn't enough draw push in it, and it's much slower than Shadowstep.  However, with K&C we got a card that adds a key missing piece: Murmuring Elemental doubles up battlecries.  This means that you can force a 4-draw and with Spirit Echo, pull Murmuring Elemental back into your hand and do it again.  Add to this that you can quickly spam out totems and drive your Thing From Below down to 0 cost, and pull that back, and potentially repeat the trick with the likes of Jinyu Waterspeaker, and you've got a winner.

This deck is tricky to play but it matches up really nice in the current meta, which is heavy with decks that like to draw.  Cube Lock and Highlander Priest are both draw-heavy decks, and it won't be obvious to your opponent at first what you're doing.  By the time they figure out that you're going to mill them, it's usually too late.

Your best mass clear in this deck is Volcano.  I use this early to keep pressure off the board and let the overload clear out.  You'll need all your crystals for late game swing turns.  Keep your hand as clear as possible.  I never hesitate to sacrifice minions to clear the opponent's board, because your Volcano is going to clean up and there's no sense wasting its hits on your own guys.  Drop a naked Flametongue Totem if you have to, in order to keep your hand clear for draw.

Early game strategy is spam out totems as much as possible and use spells to keep the board clear.  Be aware of silences and transforms that can kill your deathrattles.  You need to bounce back a Murmuring Elemental + Coldlight Oracle.  I usually do this by playing those two cards behind a taunt (e.g., 0 mana Thing From Below) and if they survive, hitting Spirit Echo and run the Murmuring Elemental and Coldlight Oracle into something ASAP to get them back into hand.  You can also use your own clears to pull them back.  

Save the Violet Illustionist for your last turn and make sure you do the math.  You'll need 8 mana to pull off your last combo, which should be Violet Illusionist, Murmuring Elemental, and Coldlight Oracle, unless you've got enough health to spare to skip the Violet and do a second Coldlight Oracle.  

Possible techs: Harrison Jones, Prince Malchezar (if you find yourself running out of cards too soon), Jinyu Waterspeaker