Seed of Salvation

If Seed of Salvation would be put into a graveyard from the battlefield, you may exile an Angel you control instead. If you do, you may activate Seed of Salvation’s ability once without paying its mana cost.
If Seed of Salvation would be exiled from the battlefield, you may pay 5 life. If you do, return it to your hand, and its mana cost perpetually changes to {3}.
{t}{w}{w}{w}: Target player gains life equal to the number of nontoken Angels you control.