Hornnnnnnn's Elemental Shaman

Wailing Caverns was able to resurrect Shaman on Standard ladder, so there's no way Wailing Vapor and Primal Dungeoneer won't make an impact in Duels, a game mode where Elemental Shaman is already fairly popular and quite strong.

Of course, go for Battlecry-related Passives like All Together Now.

Passive Treasures chosen by the player during the 12 wins run

First pool - All Together Now

Second pool - Emerald Goggles