Skor, Nature's Defiance

Whenever a nontoken creature card is put into
your graveyard from anywhere, put a +1/+1
counter on Skor if this is the first time this ability
has resolved this turn. If it's the second time,
destroy up to one target artifact or enchantment.
If it's the third time, create a 2/2 green Spirit creature token with reach, vigilance, and "{t}:
Add {g}{g}".
Whenever Skor attacks, mill X cards, where X
is his power.