According to the information provided, there were several novels that involved the King of the Undead: Summoners from the Death of Ghosts, Infinite Journey from Demon Hunters, A Technology Otaku Can Save the World, Marvel's King of the Undead, The Nine-Tailed Fox Fairy who Transformed and Traversed the Other World, and I Love Time Travel the Most. Among them, the plot and genre of each novel were different. It was recommended to choose a book that suited one's preferences. I hope you like this fairy's recommendation. Muah ~😗