C'thun isn't even necessary since most of the meta is very aggressive, but the 5-cost spells it generates can come in handy sometimes and can be followed by Anubisath Defender. Feel free to run a second Solar Eclipse instead of Kiri. Crystal Merchant is also replaceable, maybe a Steel Beetle or Groundskeeper would work. The most important part of this deck is completing the quest as soon as possible while drawing fast in order to play Oasis Surger and Nourish on curve. If you're able to, try to save an early Nature Studies so you can be able to play Nourish on 5. Make most of your healing with Crystal Power and Hidden Oasis, Solar Eclipse works well with both.