1) A really fun, interesting, out-of-the-ordinary race and/or class to play at level 6. It has to be published in an official rulebook, of evil alignment, either small, medium, or maaaybe large, and not psionic. Other than that, just about anything is game.

Drueger priest-necromancer?

I never seen one of those and it meets your requirements. And its helpful for the party.