The ending point of the Undead Unluck anime in the manga can be quite variable. Sometimes, the anime might stop before reaching a major manga storyline or might consolidate certain elements. It really varies based on the production choices.
One interesting Undead Unluck fanfic could be those that explore the backstories of the characters in more detail. For example, a fanfic might focus on the origin of Fuuko's unluck ability and how it has affected her life from a young age. It could show her experiences in school or with her family that we haven't seen in the original work.
Another way is to join Undead Unluck fan communities on social media platforms like Reddit or Discord. Fans often share and recommend their favorite fanfics in these groups. You can ask for recommendations, and they'll be happy to point you to some great ones.
Noreami's manga was not finished yet. Although the author had already given the ending in the manga, due to the complicated storyline, the manga was still being updated at a slow pace.
The first season of the Undead King had ended. It was aired in Japan on April 17, 2022 for a total of 13 episodes. The ending of the first season was an "open ending", which meant that the audience could interpret the ending of the story according to their own thoughts.
We can conclude that the three revenge comics, Chainsaw Man, Revenge of the Ironblood Sword Hound, and Revenge of Masamune, are all finished. However, the search results did not provide any relevant information on whether the novel recommendation for the revenge manga was completed, so it was impossible to confirm.