Hearthpwn

This is my take on an Omelette Cube deck.  It has a surprising amount of synergy and winning chances against all the current Rastakhan meta decks, including OTK and combo.

It's given me my highest win % on the rank 5 to Legend ladder ever and i have the hsreplays to prove it!

The deck eats hunter, shudderwock, and OTK priest.  The only losses I’ve had were vs unusually fast starts from Odd Paladin and Rogue

MULLIGAN

Keep the following:

Keleseth, 1 one mana sacrifice card, kobold librarians, tar creepers, skull of the manari, 1 egg if u also have 1 one mana sacrifice card, shriek (if against paladin only), and 1 hellfire (if against hunter only).

If you have to choose between grim ralley and sanguine reveler in the opening hand, keep the reveler.

STRATEGY

This deck seeks to stall through the early game and start setting up a board in the mid game through sacrifices of eggs, lackeys, and cubes or through skull of manari.  The size of the minions at  stage are usually enough to wrest board control in your favor.  Late game a series of doom guard into cube and/or gul’dan or contract to break up combo decks become a win condition.

As is wise with standard cube decks, doom guard  be considered more valuable than void lords.  Keep track of how many void lords and doom ghard are still in the deck.  It's embarrassing to use a lackey and whiff.  Look for opportunities to attack with the doom guard, eat it with cube, sacrifice the cube with a card, then attack with the two new doom guard.  Also remember that each void lord played dilutes the strength of gul’dan.

Early Game:

On 1 mana, Kobold Librarian is your best play unless coining for Keleseth.  The 1 mana sacrifice tools are not worth playing for their bodies.
It’s not uncommon to hero power on 2 mana (unless holding keleseth, which takes priority), but try not to hero power in the late game too aggressively. 
3-4 mana will be spent setting up eggs, tar creepers, or otherwise responding to board.
With 5+ mana, the deck starts to take over.  Look for opportunities to take board control and use the synergy and large bodies to start dominating.

Remember that unlike vanilla cube decks, this deck only adds health through Zilliax or gul’dan.  So, while hero powering through early and mid game is ok, going low health in late game can result in a thrown board state.

It's a good idea to plan out your mana for the turn before playing actions.  If you're going to hero power, do it before evrything but keleseth because it may affect your choices.

vs Hunter:  Don’t attack blindly into secrets.  Let the game go to midgame and attack into them only with inconsequential minions.  Save hellfire as a response to Emerald Spellstone.  If the game goes late, try to keep a taunt minion up at all times as they will play latge charge minions from hand.

vs slow decks: look to play aggressively in the midgame and contract away half their deck if they’re going for combo, OTK, or shudderwock.

vs Shudderwock:  Play contract earlier rather than later.  You can usually find a moment in turns 8-10.

vs Mage:  Generally not worth playing contract here.  Focus on winning in the midgame because Jaina and direct damage will make life hard late.

vs Priest:  The sooner you play contract, the higher your chance of deleting their win condition.

vs Warrior: Don't flood the board because they have mass removal and sometimes MCT.  Also it's generally better not to play contract as our deck is stronger than theirs late and because they tend to add cards to their deck with playables.  This means they will deck out later than we will.

vs Rogue:  If you know that it's quest rogue, try to keep track of and eliminate the most repetitous minions before they can replay them.  Honestly, they'll usually fall in the midgame though.  If it's kingsbane, consider trying to contact when you know kingsbane is in the deck.  Other than this, remember that thug and vicous fledgling are a win condition and need to be removed asap.

vs Paladin:  look out for level up on 5 mana.  If they go wide on 4, try to be ready for a board clear.  You should win handly if it goes late.

SUBSTITUTIONS

Skull of the Manari and Bloodreaver Gul'Dan are a must.

Prince Keleseth: Removing this frees you to use 2 drops.  Most notably defile.  I'd probably run two defiles somewhere if not running keleseth.

Spiritsinger Umbra: This card can sometimes exponentially synergize to break the opponent's back.  It accellerates voodoo doll and doubles cubes.  However, the deck will function without it.  Reasonable substitutions include saronite chain gang and spellbreaker.

Zilliax:  A swiss army knife in the midgame.  When you need a little removal, life gain, or defensive taunt, this helps a lot.  Reasonable substitutions include siphon soul, spellbreaker, and saronite chain gang

Void Contract:  The most controversial inclusion.  I do not normally advocate "silver bullets" as they generally tank win % overall.  However, in this meta and in Warlock class with its built in card draw, I believe it adds % points.  Still, I mention it here because it's a valid replaceable, if your meta is different or it doesn't fit your play style.

NOTES

If you found this useful, please consider an up vote and/or shout on twitter.  Good luck on the ladder!

-BunnyData
twitter.com/bunnydata