Heracles of the Twelve Labors

Heracles of the Twelve Labors attacks each combat if able.
Unleash (You may have this creature enter the battlefield with a +1/+1 counter on it. It cant
block as long as it has a +1/+1 counter on it.)
Persist (When this creature dies, if it had no
-1/-1 counters on it, return it to the battlefield under its owners control with a
-1/-1 counter on it.)