Robert Asprin's Myth Adventures

Start at the beginning, in Another Fine Myth, as Skeeve, an apprentice wizard, meets the demon Aahz. Though it's not love, or even like at first sight they form a connection-saving their lives-between them. Follow them in Myth Conceptions, as Skeeve and Aahz test their talent when they decide to take on an entire army themselves and continue on in Myth Directions. Then Skeeve finds himself alone with his own apprentice applicant, a king, in Hit or Myth and must deal with a medieval Mob! In Myth-ing Persons living up to one's reputation can be murder. Can a Character Assassin who tries to discredit the team in Little Myth Marker break up the team for good?