"You're going to have to define both those words for me, then," Penric said. "How you use them. But..."

"Demons start as chaos elementals, which appear from the Bastard's Hell. They can't survive without a body, and they imprint, like clay in a mold, on the mind. Usually it's an animal first; Des's first body was a wild mare. But when the body dies, they jump to what mind is more complex. It usually means that once they can jump to a human, they do. I've met a few sorcerers who are their demon's first human riders. You start to see the demon become an actual person, very like the sorcerer.

"After a few lifetimes, demons tend to develop their own personalities, beyond just a copy of their prior riders. Des is her own person, but she can mimic some of her more recent riders if I need their experience in particular. It's also why she is a 'she' -- I'm the first man she's worked with. Typically the Temple tries to match sorcerer-candidates to sorcerers of the same sex."

And honestly, Penric is surprised that it doesn't go wrong more often than it actually does. The Bastard is the god of exceptions to rules, and those who do not fit.