Gray Merchant of Asphodel 142 (Commander: Duskmourn: House of Horror)

When this creature enters, each opponent loses X life, where X is your devotion to black. You gain life equal to the life lost this way. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)

NM - $10.40
LP - $8.30
MP - $6.30
HP - $4.20
DMG - $2.10