Rise of the Rune Lords
Lace Spell: Holy
By lacing them with energy, you can add potency to the spells you cast against evil targets.
Prerequisites: Intelligence 17, Caster Level 5th.
Benefit: You give extra power to a spell that you cast against an evil opponent. You cannot lace an evil spell with holy energy. Spells laced with holy energy change the spell’s descriptor to [good] and adds a +2 bonus to the save Difficulty Class if the target or creatures within the area are of evil alignment.
Adapted from The Complete Book of Eldritch Might, page 23.