"Lord Messenger of Death, please spare my life!" This book might meet your needs. The male protagonist has a crush on the female protagonist since he was young. He has a high IQ and loves writing. The female protagonist is very powerful. The plot is full of ups and downs, and the development is also unexpected. Although it's a fantasy theme, it's not Mary Sue. I recommend it to you ~ I hope you like this fairy's recommendation. Muah ~😗