Famine (The Four Horseman Book 3) by Laura Thalassa

They came to earth - Pestilence, War, Famine, Death - four horsemen riding their screaming steeds, racing to the corners of the world. Four horsemen with the power to destroy all of humanity.
They came to earth, and they came to end us all.
Ana da Silva always assumed she'd die young, but she never expected it to be at the hands of the haunting immortal who spared her life years ago. Famine.But if the horseman remembers her, he must not care, for when she comes face to face with him for the second time in her life, she's stabbed and left for dead.
Only, she doesn't quite die.
If there's one thing Famine is good at, it's cruelty. He can't forget the pain humanity has brought him, and he's ready to bring it back to them tenfold. But when Ana, a ghost from his past, corners him for what he did to her, she and her empty threats captivate him, and hedecides to keep her around.
In spite of themselves, Ana and Famine are drawn to each other. But at the end of the day, the two are enemies. Nothing changes that. Not one kind act, not two. And definitely not a few steamy nights. But enemies or reluctant lovers, if they don't stop themselves soon, heaven will.