The Tides of Xanthia by Evelyn Briar

Rionan, the immortal Lord of Western Xanthia, is fleeing a realm consumed by civil war. Betrayed by a corrupt Lord bent on conquest, his people face annihilation unless he uncovers an ancient, hidden solution. His desperate search for answers leads him into Alianna’s world, where interest leads to obsession.
Alianna craves a life beyond her quiet routines. She seeks purpose, connection, and to do something that matters. Little does she know that when she finds a handsome stranger washed up on the sand, she is set on a path that will change her life forever.
What begins as an irresistible attraction quickly deepens. As enemies close in and the fate of Xanthia hangs by a thread, Alianna and Rionan race to uncover the knowledge that could save his realm.

Loving an immortal Lord is intoxicating. Will Alianna find the purpose she is searching for – or will this path cost her everything?