Demon's kiss - Eve Silver

As a child, Clea was rescued from a horrible car accident - and narrowly missed being killed by a demon. Now, she is one of a rare breed - a human who is able to be a Sorcerer and become immortal. She remembers nothing about the accident. But she knows she's different.
Twenty years ago, Ciarran, a Sorcerer, unwittingly rescued a human child using razor sharp strands of light and magic that have the power to kill. Or the power to heal. But in saving her, his weapon became corrupted. Now, his hand is forever tainted with evil.
Hunting a demon, Ciarran unwittingly rescues Clea again, for she was the human child he rescued so long ago. Because of her spark of magic, she is the missing link that the demons need to cross over to the Earth. They failed the first time. This time, there will be no survivors. And nothing, not the love Ciarran feels for Clea, not the inexplicable connection they feel for each other, or the loss of Ciarran's power will force Ciarran to let Clea go.