Archsibyl of Envy

Each creature you don't control gets -2/-2 for each +1/+1 counter on that creature.
Whenever a creature you don't control dies, put
a +1/+1 counter on Archsibyl of Envy.
{2}{b}{g}, {t}, Pay 1 life: Put a +1/+1 counter on target creature you don't control.