Xakar's Replenish

When this card enters your hand, reveal only this ability to your opponent, then put it face down
on the battlefield.
Choose a creature you control that would die this
turn. When it does, pay {g/w}. If you do, turn this
card face up, then, that creature gains indestructible and deathtouch until end of turn.
If the creature that this card targeted had lower
power than an opponents' creature, you gain life
equal to the difference.