I recommend "Invincible Ugly Concubine: Your Highness, Please Take This", an ancient romance novel. The protagonist, Su Zizhen, was weak and useless at first, but after transmigrating, he became the chief doctor of the underworld and took over the mess of the original body. He slapped the female supporting character and teased the matriarch. His Highness was interested in her, but she didn't want to talk to him. It showed the protagonist's development process from weakness to strength and towards the underworld. I hope you like this fairy's recommendation. Muah ~😗