Marked for the Hound by Amelia K. Oliver

Caspian finally claimed his true mate, he couldn’t be happier. But it seems fate has other ideas for him.
The road to return to his fated is a long and dangerous one. He must claim a crown he doesn’t want in order to prove himself worthy, if he can’t? Well, he will be stuck in limbo for eternity.
The marked for series follows Avery and her men as they battle for their lives against mythical creatures, both Hell-born and Heaven-born.