10. Incarnations of Immortality by Piers Anthony
"You want me to be the next Incarnation of Time?"
Oz was thirty-five. It had been fifteen years since he'd left Sunnydale for good. He thought he could never be surprised by anything after everything he'd seen. He hadn't counted on this.
Clotho, an Aspect of Fate, smiled at him. She had an Australian accent. "Yes. You're the perfect candidate for the job."
"And you know that because you've worked with me in the past, since Chronos lives backwards in time."
"Right. But you can still refuse the job, because for you it hasn't happened yet." She shrugged. "No worries."