Caelum

The Oath of the Crimson Moon
The night was tinged with red.
It wasn't the red of an ordinary sunset, but the dark glow of the Red Moon, a phenomenon that occurred only once every thousand years. Legends said that on that night, the boundaries between monsters and humans disappeared.
Lívia always believed they were just stories to scare children.
Until I find him.
Caelum appeared in his life like a shadow. Tall, with hair as black as night and golden eyes that seemed to hold centuries of secrets. Everyone in the city feared his name. Some called him a demon. Others, a cursed king.
She should run away.
But every time she saw him, something drew her closer.
That night, the ancient castle was silent. Candles flickered as Lívia walked through the empty corridors. Her heart pounded so hard she could hear it.
Then he appeared.
Caelum held her face with a gentleness that belied his reputation for cruelty. His golden eyes met hers.
"You shouldn't be here," he murmured.