I always wanted to play a Malconvoker, but my group would not have been comfortable with it. It's a class whose core conceit is that they summon demons and make pacts with them that trick the demons into serving good causes. The demons are convinced that the Malconvoker is a traditional evil cultist or self-serving wizard, but it turns out all the favours they grant them are twisted to good ends and all the prices they demand get paid in unexpected ways that turn out to be not as costly as intended.
The key stat is charisma and bluff is the most vital of skills, of course.