luthwin, Faith seeker

{g}{g}{t}: prevent the next X damage that would be
dealt to a target this turn where X is the number
of elves you control
{b}{t},Sacrifice two other creatures: Exile this card
and replace it with Luthwin, Fulfiller of sacrifice
for the rest of the game.
If there is an angel on your battle field at the beginning of your endstep you may exile this card
and replace it with Luthwin, Salvation's Proof