Well, 'The Unholy' is purely fictional. It was crafted by the imagination of the writers and not inspired by any actual happenings. The story and its elements were made up for entertainment purposes.
In most cases, 'Unholy' is not rooted in real events. It's probably the product of the creator's imagination and creative process. There's no evidence suggesting it's based on actual happenings.
A death knight, known as Damian, had lost his humanity long ago. But when he entered a small village, he saw a girl named Lyra. She didn't cower in front of him like others. Instead, she showed him kindness. Damian found himself falling for her. Their love story was a slow burn. He had to fight his inner darkness to be with her. Lyra, on the other hand, had to convince the villagers that Damian was not all evil. In the end, their love prevailed.
Here are a few novels I recommend for you: Genie from Marvel, I am the Death Knight, The Female Death Knight of the Other World, and The Death Knight of Marvel. These novels all had plots about Death Knights. I hope you like this fairy's recommendation. Muah ~😗