Unholy Bride

At the beginning of your turn, lose 1 life.
{t}: You and target player each lose 4 life.
At the end of your turn, target a card in your graveyard then reveal the top card of your library.
Gain life equal to the difference in mana cost
between both cards. If this difference is 2 or less
take the targeted card into your hand. This ability triggers only once per turn.