Mulligans
So the whole Core for Priest’s Core Set is that you just want to race to the Finish with C'thun, the Shattered in hand. And you have as much Card Draw possible to make it happen. But one Burn from ANY of the C’Thun Cards and you have to concede, so becreful with what you draw. That is why you must use Malygos the Spellweaver with SOME levels of caution. He will very glady help you along your Exodia Stredagy, but he may also just as well screw you completely over if you are super unlucky. You also have Focused Will just in case for your Gadgetzan Auctioneer to shut up, when you’re down drawing out your cards to dig for C’Thun. And with Rally! in play, you can summon up to a Crimson Clergy, which will act as a soft taunt for you, but your important cards are Sethekk Veilweaver for the extra extra generation, and the most important being Nazmani Bloodweaver to discount your spells as effective as possible.