Dark Skye by Kresley Cole — book slip

Though centuries have passed since Thronos, Lord of Skye Hall, lost the one woman meant for him, nothing can cool his never-ending need for Melanthe. She was the girl he loved and lost as a boy, the girl who nearly destroyed him.

Desperate, yearning Lanthe, a once-powerful sorceress struggling to reclaim her gifts, has never forgotten Thronos, the fallen angel who protected her until she was ripped from the shelter of his arms.

Friends to enemies to lovers, with their families at war and the world burning around them, will they succumb to the brutal chaos that threatens everything they cherish? Or can the two rekindle their childhood love in time?