Thanatos, Death Realized

+2: Sacrifice all creatures you control, put tokens on the field that are copies of creatures sacrificed in this way.
-3: Destroy X target permanents, where X is the number of permanents sent to any graveyard this turn.
-15: Destroy all permanents, then create an X/X black Horror token with Trample and Menace. X is the number of permanents destroyed by this effect.