Ezhak, The Writhing Moon

Prevent all damage that would be dealt to players
that have any other creatures under their control,
for each damage prevented, put a -1/-1 counter
on each creature that player controls.
Ezhak's power is equal to the number of -1/-1
counters on creatures.
When Ezhak deals combat damage to a player,
remove all -1/-1 counters from creatures you
control.