Hearthpwn

So, I've been working on that deck for a while, because I got Zerek as my free legendary after the update and wanted to make him work. The idea behind this card for me is great because the priest has so many spells and with the right cards you can make a good deck around him. Maybe it is not a top  tier deck, but it is a lot of fun to play it. 

In the beginning you hold on to  the Shallow Gravedigger, Death ringer and the Crystalline Oracle. You must summon at least 2 of those, so with the help of Twilight's call you can complete the quest quite easy. The Death ringer is an awesome card for the Quest priest. It gives you presence on the field for 2 mana and also draws a deathrattle minion from your deck. The Crystaline oracle often gives you some good cards from your opponent, so it is a must for this deck. 

The two Dustbreakers are one of the first choices for almost every Priest deck

The Gigling inventor is one of the best cards from The Boomsday project and in this deck it can save you when you don't draw the cards needed for the completion of the quest. 

The Rotten Applebaum is also a good value card for this deck - Taunt, heal and also helps with the quest. Bone drake is also very helping. Also sometimes gives you precious draggons when it dies.

So, when you complete the quest, don't rush the Amara. Use it only if it is your last chance to survive. If you are not gonna die the next turn, combine it with the Baleful Banker for an extra copy(maybe Zola is better, but I still don't have it, so I just use the Banker). 

And now the win condition. Zerek, combined with Vivid nightmare gives you almost an infinite value.( Get extra copies of the Vivid nightmare with Shadow visions). When the opponent tries to kill your Zereks, they ressurect. Play Alextrasza and there you go. If they manage to kill your Zerek, revive him with Eternal serviture. One last thing about Zerek. 1 Zerek+1 Vivid nightmare gives you 20 damage in two turns. Very often at least one of the Zereks survives the next turn. Then you cast another Vivid nightmare on him and so on. Extra arms also has good synnergy with him.

 P.S. I added Zerek's cloning gallery, one more Obsidian Statue and a Guilded Gargoyle. It is more consistent that way.