Vile Spell Ring

Book of Vile Darkness 3.5
By Monte Cook 

If this ring is worn by a spellcaster, 1 point of damage per spell level from each of the caster’s damaging spells is vile damage. If multiple creatures take damage (such as with a fireball spell), each creature takes the vile damage.

Caster Level: 5th; Prerequisites: Forge Ring, Vile Lance; Market Price: 15,000 gp.