Hearthpwn

How to play the deck: A ramp deck using big Taunt minions to destroy your opponent and then destroy your enemy with C'Thun.

C'Thun and the Followers

C'Thun: The finisher of the game. But you have to realize you don't need C'Thun to be a 30/30 to win the game. You already have efficient monster that can weaken your opponent for you. Treat C'Thun as the new Force of Nature + Savage Roar.

Beckoner of Evil, Twilight Elder, Disciple of C'Thun: Typically early game C'Thun buffers. Just the best  in slot. Staple of most C'Thun decks.

Klaxxi Amber-Weaver: it isn't very likely to reach 10 attack when it is on curve, which is why there is only one copy of this card. Druid has alot of good 4 drops, so this card is one of the weaker ones.

Dark Arakkoa: Best buffer of C'Thun. It makes the 10 attack C'Thun threshold easy to reach. This is the reason why we play Druid C'Thun.

Twin Emperor Vek'lor: Another C'Thun Staple. Getting 10 attack is easy with Dark Arakkoa and then you get double Taunts of value.

Brann Bronzebeard: Honorary C'Thun follower. He is going to be a staple in C'Thun decks. Just double your buffs and make Disciple of C'Thun a mini Fire Elemental

Ancient Harbinger: They have to answer this or you get C'Thun. A clear include in C'Thun decks. 

The Ramp

Innervate, Wild Growth: Typical ramp

Mire Keeper: A very flexible card. You can get more bodies if you need to fight Zoo or Shaman. Or just ramp if your are not under pressure.

Nourish: Either you skyrocket your ramp, or you use it in the later stages of the game to dig your C'Thun. With the huge amount of Taunt the deck has, it is safe to use it to draw in the late game.

Druid Staples

 

Raven Idol: Works very well with Frandral

Wrath, Swipe: Removal Package

Druid of the Claw: He just have better stats and is more flexible than Crazed Worshipper. You don't have to all in on C'Thun. You just need to play good cards to win a game.

Ancient of War: Another big card to ramp into. With the huge amount of Taunt the deck already have, this can be replaced for something else. You just want another big card.

Frandral Staghelm: Like Brann, he just makes your card better. You don't need to build a deck around him to get value. You got the Mire Keepers, the Druid of the Claw and the Wraths.

Other

Azure Drake: No Ancient of Lore means we lack card draw, which is important when you need to dig for C'Thun. Spell Damage works very well with Swipe and Wrath.

Soggoth the Slitherer: Surprisingly powerful in this deck. With a deck with some many taunt minions (Druid of the Claw, Dark Arakkoa, and Twin Emperor Vek’lor), it is very easy to get your opponent to use their Black Knight on those instead and then have no answer to Soggoth. Without being able to use spells, they have no choice but to waste this minions on this brick wall.

Cards to Consider

Living Roots: You need it if Meta becomes more aggro. Aggro Shaman, Zoo and Aggro Paladin are mostly likely contenders for aggro in the Standard.

Spellbreaker, Keeper of the Grove: Deathrattle Rogue or Hunter can be too prevalent in the new meta.

Doomcaller: So you can replace Ancient of Lore for this. But I strongly disagree. With how this deck is played, you didn't need to recur C'Thun. You want to beat down with your stat effective monsters and then just finish them with C'Thun. C'Thun should be the last thing you play. Also the turn you play Doomcaller, he does nothing. That isn't something that you can allow if you happen to be behind on the board even slightly.