This a priest deck build around the shadowform card. The idea is that the shadowform hero power, once fully developed, is the ultimate control power over the board. To get there you will need to stay alive with the help of the heal card and all the boardclear spells.
As win condition there is the mindblast + smite + prohet velen for 14 dmg combo, or you outcontrol the opponent into fatique as there is no card draw in this deck to assure this win condition.
This deck got me into legend and I got positive feedback of defeated opponents who liked to have faced an unusual deck.