Wretched Curator (Story)Source Agents of Evil pg. 9
Some fools fear the written word, but you that understand knowledge—all knowledge—is a valuable tool, and restricting it out of superstition is abominable in your eyes.
Prerequisites: You must have purchased a scroll or spellbook containing a spell with the evil descriptor in a place where such dealings are illegal, or must have the Secret Society Inductee or Diabolical Upbringing background.
Benefit: You can always purchase potions and scrolls of spells with the evil descriptor at a 10% discount, even if they are not normally available in a settlement because of its size or the local laws. You gain a +4 bonus on Knowledge (arcana), Spellcraft, and Use Magic Device checks related to spells with the evil descriptor or evil written works.
Goal: You must own scrolls of spells with the evil descriptor or tomes of forbidden lore worth a total of 50 gp per character level, and be the primary caster of a successful occult ritual (Pathfinder RPG Occult Adventures 208) of at least 5th level that has the evil descriptor.
Completion Benefit: Every time you cast a spell with the evil descriptor, you can remove that descriptor from the spell and treat yourself as a neutral-aligned caster for the purpose of determining the spell’s effects, circumventing defenses such as protection from evil and preventing detection via detect evil and similar effects. If you cast a spell with the evil descriptor and do not remove that descriptor, you instead gain 2 temporary hit points per spell level. These temporary hit points last for 1 hour.