Karthul, the Darkbringer

Your spells have Cipher. When you encode a spell
for the first time, put it back in your hand. Give
your creatures +1/+1 for each encoded spell.

When Karthul attacks, sacrifice a creature and create a 1/1 black creature token that is all creature types for every creature you control.

When you sacrifice a creature, put an encoded spell into your hand.