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 - $7.70
LP - $6.10
MP - $4.60
HP - $3.10
DMG - $1.60