Califax, The Bloodweave

Flying, trample
Non-demon creatures you cast cost {1} less to cast
for each contract you pay. (Contracts: Discard a
card, pay 2 life, and/or sacrifice a creature.)
Whenever you pay a contract, put a +1/+1
counter on Califax, The Blood Weave and note
it. At the end of your turn, exile that many cards
from the top of your library.