Naven, The Guilty

Whenever Naven, The Guilty or a black source you control destroys a creature, exile X cards from your graveyard. You may then return an amount of creatures from Exile to your hand equal to the amount of counters on Naven, The Guilty. If you do, place a stun counter on Naven, The Guilty. If you don't, give Naven, The Guilty X +1/+1 counters.
—
"I'm sorry, my Lord. If you cannot forgive me, then perhaps... he will."