The Runemaster Series by Katharine Kerr

Secrets are Dangerous Maya Cantescu, an art student in the San Francisco Bay Area, has more secrets than she can handle. Some she keeps from herself, like her mysterious talent for sorcery. Some she knows too well, like the rare disease that threatens to kill her-or someone else. When she meets Tor Thorlaksson, a sorcerer and runemaster, he seems to offer an escape from her deadly problems. But he knows secrets about them both, and these could turn her world upside-down.

Art student Maya Cantescu has always had secrets to keep--her mysterious disease that has turned her into something like a vampire, her father's obsession with ritual magic, her own talents for the occult. Now, however, she has a secret far more dangerous than those: in self-defense, she killed a man with magic. Can her lover, the wealthy, powerful runemaster Tor Thorlaksson, protect her from the consequences? He has dangers of his own to face, because his family's evil past haunts him... moreArt student Maya Cantescu has always had secrets to keep--her mysterious disease that has turned her into something like a vampire, her father's obsession with ritual magic, her own talents for the occult. Now, however, she has a secret far more dangerous than those: in self-defense, she killed a man with magic. Can her lover, the wealthy, powerful runemaster Tor Thorlaksson, protect her from the consequences? He has dangers of his own to face, because his family's evil past haunts him. Worst of all, a powerful spirit from the mists of time is hunting Tor down, in hopes of taking him away from Maya and making him her own--forever. less