I recommend novels like " Killing Maru and Ling " and " Killing Qianmo and Hua Qian ", where the male protagonist is handsome and the female protagonist is emotionally closed.

He could try recommending the book "How Can The Ruler Marry Only Me". The male lead was a god of war known to the world. His heart was as cold as ice, cruel and violent, while the female lead was the king of the 21st century secret agents. She had bloodthirsty and ruthless methods and a calm and witty mind. It was very similar to the setting mentioned in the title where the male lead was beautiful and the female lead had a machine-like heart. Their relationship was very complicated. The male lead only had a soft spot for the female lead. For her, he was willing to go to hell. The entire plot was filled with killing, power, conspiracy, and emotions. It was very exciting. I hope you like this fairy's recommendation. Muah ~😗