Can I kindly ask that some of you test this list (adjustments welcome, I'm refining it after all) but I would like to see how it does against different ranks (I'm currently 13).
The goal of the deck is to beat the opponent with their own resources as you efficiently use your own. Draw the game out and survive against aggro, and either pressure out combo and control decks or steal their win condition(s) and win by default or fatigue.
While the deck had an abundance of fuel, actual card DRAW is rare which means the initial mulligan often decides the game. Feel free to look into tech options for poor matchups, but I'm just trying to make a core list right now.
Why Mountain giant? The strength of the card comes from the potential early drop by t3 or t4 (maybe t5) where a 8/8 can be hard to deal with. However, that requires early card draw which, from the top of my head, only mage and warlock can do at the moment. This seems like a tempo deck that wants to compete for the early came and that means you can't play an early Mountain giant.
Holy Water is just a slow and situational card. If you want to steal things Seance is just a better option as 5 mana is a lot.