The Darkangel — Meredith Ann Pierce

Aeriel remembered the first time she had seen the vampyre, a creature with wings as deep and dark as the sky. They drank the light and diminished it; they were wings of pure shadow. It was only when those wings unfolded that Aeriel discerned the figure of a man. Never before had she seen a living being so cold and evil . . . or so compellingly handsome. His magnificence, his splendor and sureness, took her breath away. When he looked at her, her strength failed her. She could put up no struggle as he folded her in his wings and carried her away.

Aeriel had set out firmly resolved to destroy the vampyre and free the wraiths--thirteen pitiful creatures, once the vampyre's beautiful young brides, whose souls are imprisoned in lead vials hanging from his neck. But now that Aeriel herself is his captive, she finds she can do no other than obey him, even while she knows she should long wholeheartedly for his destruction. In order to save herself, and, in fact, her very world, her quest must be to kill him before he takes a fourteenth and final bride.