Overworlder

Whenever a creature you control dies, put a
+1/+1 counter on Overworlder equal to that
creature's power
Remove X +1/+1 counters from Overworlder,
return a creature with power/toughness X
from your grave yard to the battlefield. Put
half X +1/+1 counters on it
"End the suffering of our kin"- Overworlder
summoning incantation