Book of Mercenaries: Xyrella - Priest
Not only is it Patch day with the introduction of the Wailing Caverns Mini set, it's also a new chapter in the Book of Mercenaries, with Xyrella, the Priest going live today!
Quote from Blizzard
Book of Mercenaries Xyrella – Live with 20.4 Patch
The Draenei called it The Night of Falling Stars, when shards of fractured Light rained across Azeroth. Guided by a mysterious voice, the priest Xyrella now searches the Barrens for the glowing shards which the voice promises can save her daughter's life. The priest's quest will be explored in Book of Mercenaries Xyrella, launching June 3rd. Defeating all 8 bosses in this linear adventure will reward 1 Priest pack, containing only Priest cards from Standard!