Curse of the Coral Bride — Brian Stableford

In the far future, Earth is slowing dying, as the Sun has turned into a red giant that threatens to explode. The last inhabitants of the planet have no idea why they're still living, and why they seem to have been made in the image of earliest man--and not the countless human species that have existed since. But they still have to time to ponder, and time to kill--and they do so in the traditional way, by killing each other! This isn't an hospitable Earth, even for magicians--especially a well-meaning one--but Giraiazal of Natalarch is determined to do the best he can to keep on cheating Damozel Fate, in spite of her nasty tricks, until the very end...or at least as close to the very end as he can get. A sweeping fantasy novel of the end of the world, in the style of Jack Vance's classic The Dying Earth.