When Verdurous Gearhulk dies, its persist ability triggers, returning itself from your graveyard to the battlefield with a -1/-1 counter on it.
When Verdurous Gearhulk enters the battlefield, it triggers, putting a +1/+1 counter on itself and Zealous Conscripts, and two +1/+1 counters on any other creature(s) you control.
Repeat.
Results
Infinite +1/+1 counters on all other creatures you control.