Holding a 10 drop would normally be a really bad idea; but you want to drop C'Thun on turn 10, everything else is just to help you mop up early game minions and hope you draw some good early game minions yourself.
Anything just to try and remove minions from the board until you can try and get some breathing space with the Crazed Worshipper or Brawl ... though this deck really doesn't fare well against Warlock Zoo.
Again it’s heavily reliant upon C'Thun – which means Priests will give you problems as playing C’Thun is extremely risky – Mind Control for instance, you can steal it back with Sylvanas Windrunner though.
The early game is a tit-for-tat minion battle but Brann Bronzebeard can give you a little extra value by doubling up on battlecries – especially with Disciple of C'Thun. Fiery War Axe and Shield Slam early on can really turn the tide in your favour.
Ideally you want to drop C’Thun as soon as you can to use as a board wipe more than anything else – then get him back with Doomcaller to use as a finisher later on. If someone is foolish enough to let you keep Bran on the board on turn 9, you’re laughing!
— Updated —
Swapped out TBK for Elise Starseeker; she’s not situational and has useful stats to put on the board on turn 4… and she opens the additional option of going Golden Monkey > Legendaries. The biggest drawback with Elise was always that, once played, your opponent will try and kill as fast as possible before you can draw the Golden Monkey and that changes the style of the game to one you’re not necessarily suited to.
However, practically everyone will try and kill you as fast as possible once they’re realise you’re running a C’Thun deck anyway so there’s no drawback to adding Elise.