Black Sea: A Forbidden Enemies-to-Lovers Dark Romantasy with Morally Black Villain

Darkness shall swallow her whole.

An elf princess. A human soldier.
A forbidden passion.
An ancient, dark enemy prepared to do anything to take the power back.

I met him on the battlefield as the flood was about to overwhelm us.
I found myself saving his life.
I chose him over my people.
I don't know why.
Now I'm the one who has to trust him to survive in a foreign land. Yet the closer we get, the more unbearable the attraction I feel for the human becomes.
I know it's forbidden.
But every look, ever...