Every expansion I like to play reno paladin with 30 legendaries because reasons.
This deck is obviously expensive and should only be played for fun.
Sir Finley of the Sands, Zephrys the Great, and Siamat are the new cards from this expansion that help this deck out a lot. Generally speaking, the cheaper your legendary minions the better, but having N'Zoth support is important for the deck to have late-game power.
When playing the deck, you generally want to mulligan for your cheap cards like Sir Finley and Zephrys and try to curve out from there. You will lose most of your games but you will have fun with the games you win.
The upgraded hero powers that are best are Warlock and Mage generally.