Fiendish Magic

Mortals have choice, and some choose to be Evil. Fiendish Magic is awarded by the The Powers of Hell upon select mortals. These gifts come with a price.

A spellcaster cannot choose Fiendish Magic spell as one of the free spells gained upon raising level, unless the spell has already been bargained for from a Fiend or Mentor.

Otherwise, a spell could be learned from a Fiend, Mentor, or discovered in a spell scroll, spell book, etc.