Betrayer's Mercy/Wrath

Gain {x} life where {x} is the number of Betrayer's Magic cards are in your graveyard.
Mercy: {p/g}{g} double the life you gain from this spell.
Wrath: {p/b}{b} deal damage to target minion or player equal to the health you gained.
(you can choose Mercy or wrath)
"The Betrayer could be merciful, but his mercy can quickly turn into Wrath" Malfuriun Stormage