Premise:  Quest Priest is good late game, and Zephrys/Barista Lynchen is so good that you can build a deck around it. 

Mulligan for healing, Northshire, PWS.  VS aggro, keep Pyromancer, as it's one of the best draw enablers + board clears. 

Funny enough, I've noticed people straight up not attacking in order to "play around" completing the Priest quest.