Astalos, Shock Reaver

Flying, haste
Whenever Astalos enters the battlefield or
attacks, put a shock counter on it. Astalos has
+1/+0 for each shock counter on it.
{r}, remove a shock counter from Astalos:
astalos deals 2 damage to any target.
{4}{u}: draw a card. This ability costs {1} less to activate for each shock counter on Astalos.