I have had a lot of fun with this Demon Hunter build utilizing the Deathrattle strategy.  I was a big fan of the OTK deck before the expansions cycled last month and I wanted to play a C'Thun deck that was pretty fun... And here we go.

The theme of the deck is to control as much of the board as necessary and then unleash C'Thun, the Shattered to drop your opponent.  That's not to say that you cannot just outright kill your opponent with the board threats that you may not have to pay to get on the board in the first place. Nonetheless, it works pretty well and I like it. 

The deck really blooms from taking advantage of the Deathrattle mechanics from this last expansion.  And seriously, dropping Death Speaker Blackthorn to help thin your deck by 3 minions that could also help pull stuff from your hand is invaluable.  The DH Deathrattle package minions are there to continually add value to having stuff in your hand.  Which for Demon Hunter isn't a problem since it cycles through it's deck so quickly anyway. 

The Sigil of Flame works surprisingly well at keep your opponent's drops to a minimum for a turn that it is a crime.  Having that on the board has kept many a Rogue from dropping their watchposts for me to annihilate the following turn.

Illidari Studies is just a fantastic card that can help you to get the outcast card you need for the situation.  The only thing I would make sure you do with this card is NOT fire it off immediately so that you can actually use the outcast card you get from the discovery.

Anyway, I will be updating some of the swap outs and cards that may not have worked as well as I have wanted etc as we go.  In the interim, I hope you enjoy!

Mulligans: 

You really want to try and get an outcast card on the far left side of your opening hand.  It just makes things easier.  Against minions aggro decks, you want to try for the Immolation Auras and Sigil of Flames.  These two cards alone are enough to cause most aggo decks to just halt in place

Keeping a deathrattle minion in your hand is key.  That way, when a Razorboar or Razorfen Beastmaster trade you not only nuke a minion on their board, you get a replacement without having to spend mana on it. 

I have yet to have a situation where keeping the high cost Death Speaker Blackthorn in an opening hand has been a bad idea.  Yes it is a dead card for essentially 7 turns.  HOWEVER, since the rest of the deck cycles through so well, I've not worried about it much.  Add that it thins out my deck by up to 3 cards allowing me to draw into my C'Thun pieces...   The caveat to that is that I have also drawn it on turn 5 ( with The Coin ) and with Skull of Gul'dan and it cost substantially less.  So this is a toss up and your call.

Vs paladin.. in all cases keep your Aldrachi Warblades and your Tuskpiercer.  One allows you to target problematic minions like Crossroads Gossiper with your hero power as well and get your life back, the other helps to thin your deck and get the taunting/life gaining minion Death's Head Cultist ready to be dropped from a deathrattle ability.

***UPDATE***

vs. Mage:  Honestly this is all about drawing through your deck better than your opponent.  What I have discovered is that bating their Counterspells is key.  The last thing you want is to have a part of your C'Thun, the Shattered combo stopped short like that.  Since they have minimal minions except what is brought in from Font of Power and Apexis Blast you can just start slaughtering their face with minions.  I also use Sigil of Flame as great Counterspell and Netherwind Portal bait. 

vs Paladin: This comes down to controlling the field, which is what this deck does.  As long as you be careful with the Oh My Yogg! to not grab your c'thun pieces, there is enough board clear and draw to outlast your opponent.  Of all the times against Paladin, I've not lost yet, but tomorrow's another day

vs Rogue: This is just funny.  The only thing that slows you down is Far Watch Post because of the increased cost for cards drawn so that means this card is a priority to nuke.  BUT, once that is out of the way, you are golden.