Awaken the Highland Warrior by Anita Clenney

A man from another time…
Faelan is from an ancient clan of Scottish Highland warriors, charged with shielding humanity from demonic forces. Betrayed and locked in a time vault, he has been sleeping for nearly two centuries when spunky historian Bree Kirkland inadvertently wakes him. She’s more fearsome than the demon trying to kill him, and if he’s not careful, she’ll uncover the secrets his clan has bled and died to protect…

Could be the treasure she’s been seeking all her life…
When Bree inherits an old treasure map, she discovers a warrior buried in her backyard. But the warrior isn’t dead. Bree shocks Faelan with her modern dress and her boldness, and he infuriates Bree every time he tries to protect her.
With demons suddenly on the move, Bree discovers that Faelan’s duty as protector is in his blood, and that her part in this fight was destined before she was born. But nothing is ever what it seems…