Archfiend of the Masses

Flying
When Archfiend of the Masses enters the battlefield, put any number of -1/-1 counters on creatures you control. For each creature with a
-1/-1 counter, Archfiend of the Masses gains a
+1/+1 counter. Creatures you control with a
power of 1 gain wither.
"Unified by your suffering, you will be redeemed"