Wait, that's 3 damage from wraithlings + 2 from scorn + 12 from deaths + 2 from general. 19 damage is 1 over lethal.
Equips the artifact and trade wraithlings. You would have 3+6 damage and 3 mana left. BBS and sacrifice one wraith to play a scorn, leaving you with 4+1 more damage and 1 mana. Then, sacrifice the scorn to play a second scorn, leaving 2+1 damage and spending all mana. Add 2 more damage from Lilith herself, and you have 1 over lethal
P.s. This should be a spot the lethal challenge