White Chaos Emerald

Whenever a creature you controls dies, or is
exiled, you gain 1 life.
Whenever an opponent casts a noncreature spell,
White Chaos Emerald deals 1 damage to that
player.
Whenever you gain life, you may pay {1}{w}. If
you do, put a +1/+1 counter on target creature
for each 1 life you gained.