Abednego

Abednego is the Last of the Herd, his noble race all but destroyed by mortals in the Hunts of the Middle Ages. By the revolutions and collapse of monarchy in Europe, he'd become convinced he was the last of all Guardians, a species derived from the hybrids of Angels and human women in Genesis. The great men of old, monsters called Nephilim. All Guardians fell eventually if they didn't find their mate, the one person who could invoke their name and prevent them from committing heinous atrocities. Their keeper.
Abednego hadn't hoped to find his. After all this time? For what conceivable purpose? It was absurd! Wonderful, but absurd.
But he had, in an American Soldier who had managed to fall into the clutches of a troupe of Nephilim. One he'd been trying to free for six months.
And Private First Class Samantha "Sam" Trent was having none of him. Brainwashed, tortured, mostly dead and delirious from her ordeal, she bolted with what little strength she had left.
Straight into the ruins of Hiddenrealm, the ancient Kingdom of the Fae.

They were not alone, and they both have to learn to understand each other as Abednego tries to coax Sam back into his protection and Sam tries to rationalize this surreal new world.