Imagine a ghost chef in the mansion's kitchen. He creates delicious but also cursed food. If Luigi eats it, he gets strange powers or drawbacks. And a ghost librarian who guards the secrets of the mansion in the form of books. Luigi has to deal with the librarian's tricky questions to access the knowledge he needs to progress in his adventure.
A talking portrait that gives Luigi hints and clues. It could be a former owner of the mansion who is now trapped in the form of a portrait. Another interesting character could be a ghost dog that befriends Luigi and helps him sniff out hidden items or ghosts.
Luigi is the central character in the Luigi's Mansion Dark Moon story. He is the one who is called upon to solve the mystery of the shattered Dark Moon. There are also Professor E. Gadd who provides Luigi with the tools like the Poltergust to help him in his quest. And of course, there are numerous ghosts which range from common ones to more menacing boss ghosts. These ghosts are the ones that Luigi has to capture in order to complete his mission.
The story is about Luigi being called to investigate a series of hauntings at Evershade Valley. He uses his Poltergust to capture ghosts and solve the mysteries. There are different mansions with their own unique challenges and ghost types. Luigi has to face all these spooky situations to restore peace in the valley.
A little ghost girl who was once a princess in the mansion before it became spooky. She could help Luigi navigate through the more dangerous parts of the mansion because she knows all the secret passages. She's not really evil like the other ghosts, just a bit mischievous.
One idea could be exploring Luigi's character growth. Maybe he discovers a new power within the mansion that helps him face his fears more bravely. Another idea is to create a backstory for the ghosts in the mansion, like how they came to be there and what their lives were like before. A third idea could be a crossover where characters from another game enter Luigi's Mansion, creating new and exciting adventures.
A plot could revolve around Luigi having to rescue all the Toads that have been scattered throughout the mansion in different forms - some are invisible, some are trapped in paintings. As he searches for them, he uncovers secrets about the mansion's original owner and their dark past.
Maybe an OC that is a ghost hunter from another dimension comes to Luigi's Mansion. This OC has advanced ghost - hunting tools and techniques that Luigi has never seen before. Together, they team up to face an extremely powerful and malevolent ghost that has been terrorizing the mansion for a long time.
In this fanfiction, Luigi might be exploring the mansion when he stumbles upon Tails. Tails, being the tech - savvy character he is, could help Luigi figure out the strange mechanisms in the mansion. Maybe they'll find hidden passages together and encounter some spooky but friendly ghosts.
A ghostly child would be a great character. This child is lost in the mansion, not really understanding that they are dead. The OC could try to help the child find peace. Also, a reclusive historian who has spent years studying the mansion from afar. He is reluctant to enter the mansion at first but is drawn in by the OC's adventures and his own thirst for knowledge about the place.
Mario would definitely be a main character. Since Luigi is his brother, he would be the one most concerned about Luigi's transformation and would do everything he could to help him. Princess Peach could also be a main character. She might offer her castle as a safe place for baby Luigi and use her resources to find a solution. Toad could be there too, helping Mario with taking care of Luigi and providing useful information about the kingdom that could lead to reversing the spell.
One of the top stories could be the encounter with the various bosses on different floors. Each boss has its unique design and backstory, like the sea - themed boss on one of the lower floors. Another top story might be Luigi's exploration of the different themed floors, such as the spooky circus floor.