Blade of Darkness by Dianne Duvall

Dana Pembroke has been able to glimpse the future of those she touches for as long as she can remember. But she never saw Aidan coming. When the tall, dark Celt with the charming grin yet world-weary eyes walks through her door, the future she sees for him is one full of violence, danger, deception… and passion. Because amidst the terrifying battles that unfold in her visions, she also sees herself in Aidan’s arms and in his bed. Dana knows she should keep her distance, but the tender moments and laughter they share entice her even as she finds herself thrust into a world of vampires, immortals, and other preternatural beings.

Immortal Guardian Aidan O’Byrne has been hunting and slaying psychotic vampires for nearly three thousand years, so visions of bloody battles don’t trouble him. The battles Dana foresees, however, show Aidan’s brethren turning against him, so he can’t help but feel alarmed. While he spends as much time as he can with Dana, struggling to decipher her dire predictions, Aidan finds himself utterly smitten. Hope rises that he has finally found a woman who can banish the darkness and loneliness that plague him. But when vampires begin targeting Dana and a powerful enemy spawns chaos, will fate grant them time to find happiness together?