Was the Seraphim novel over? Why was the plot of a novel different from that of a manga?

The Final Seraphim novel was not yet finished because the author, Oda Kiki, had not announced the final ending of the novel. Moreover, because the plot of the novel was different from that of the manga, it was impossible to give a simple and definite answer. In the novel, the plot changed a lot, especially in the development of the characters. The manga retained many plots that were not shown in the novel, such as the battle between the main characters and the Demon King. These differences might cause readers to have different views on the ending of the novel and the manga. The changes in the plot of the novel and manga were also the result of the author Oda's constant exploration and adjustment during the creation process. He hoped to present a more complete and vivid world for his readers, so he might add more details and plot changes in his subsequent works.