Primeval Faith-stone

Whenever a creature you control leaves play, if
it had any +1/+1 counters on it, put that many
ritual counters on Primeval Faith-stone.
Whenever you cast or copy an instant spell, you
may remove up to X ritual counters from
Primeval Faith-stone, where X is that spell's
mana value. If you do, put that many +1/+1
counters divided as you choose among creatures
you control and you gain that much life.