There's a novel, I can't remember the name. The female lead is called Xia Xue, and I can't remember the male lead either. But there's a character in it called Hong Wen. He later became a monster.

According to the information provided, I think you might be describing the modern romance novel,"Sleepy Love." In the book, the female name was Xia Xue, and the male protagonist's name was not mentioned. However, the character Hong Wen described that he later became a monster, which was in line with the plot of the book. I hope my guess can help you. If you like this topic, I can recommend more similar novels. I hope you like this fairy's recommendation. Muah ~😗