Pale King

As long as your creatures have total power of ten or
greater, this creature has hexproof.

{x}: creatures you control gain hexproof from
spells and abilities with mana value X.

at the end each of your turns, if no creatures
you control died, put a +1/+1 counter on
each creature you control. If any creatures
died, put a -1/-1 counter on each creature
you control.