Nicholas Eternal (The Wayward Saviors, Book One)

Nicholas Theodoulos is an immortal savior in desperate need of saving. All the power, wisdom, and even the favor of the gods is not enough when 1,700 years of heartache have left marks on his soul. But Noory Abramson, a streetwise woman with a sacred tattoo and a touch of grace, steps from the shadows, not knowing if she's arrived in time to save him or end him for good. With a heart grown as heavy as his, either fate might do.
When Noory observes Nick grieving over the body of a young girl in a deserted Atlanta alley, she isn't sure whether he is friend or foe. However, she quickly realizes his special powers to rescue children and rain down vengeance on those that harm them may be the only thing that can help her when one of her charges, sixteen-year-old Grace, goes missing from the local homeless shelter. Soon, Nick discovers Noory has secrets of her own: one that might lead him to redemption, and possibly love, for the first time in his painful existence.
In their world, a gift looks a lot like a curse, and Noory must reach Nick before his gift consumes him.