Befana can be a magical helper. In fanfiction, she often uses her powers of flight and gift - giving to assist Ladybug and Chat Noir. For example, she might give them a magical item to defeat a particularly tough akuma.
Some Befana fanfictions focus on her backstory in relation to the Miraculous Ladybug world. For example, there's a story that delves into how Befana came to know about the Miraculous and her connection to the ancient magic that might be related to the Miraculous powers. It gives a whole new perspective on the character and the overall lore of the show.
Well, Ladybug could be seen as a new type of Gem. Her powers are magic - based, similar to the powers of the Gems. She might be mistaken for a powerful new Gem at first. Cat Noir could be like a fusion of sorts, with his cat - like abilities and charm. He could team up with Amethyst, for example, as they both have a bit of a wild side.
This event in the fanfic could also lead to new characters emerging. Maybe someone would try to take on Ladybug's mantle in a different way. Or new villains could rise, seeing the opportunity in the chaos. The magic of the Miraculous might be affected too. Since Ladybug was an important part of the magical balance, her death could have unforeseen consequences on the powers and the Miraculous themselves.
One idea could be a crossover where Ladybug and Cat Noir end up in the world of Steven Universe. They could team up with Steven and the Crystal Gems to fight a common enemy that has the power to disrupt both their universes.
Well, perhaps she's a mentor figure. Since she has a lot of experience in the superhero/villain world in the Marvel universe, she could teach Ladybug and Chat Noir new fighting techniques and strategies to outwit their enemies.
Tikki and Plagg could have interesting roles too. Tikki, being the kwami of creation, could help Marinette come up with ways to interact with the Phantom and the other characters in the Phantom of the Opera world. Plagg, on the other hand, might be a bit more mischievous. He could accidentally cause some chaos that either makes the situation more difficult or surprisingly helps in some way. For instance, he might steal the Phantom's mask as a joke, which could lead to a whole new set of events.
Creepypasta can add a sense of horror and the macabre to Miraculous Ladybug fanfiction. It might change the tone from the light - hearted and magical feel of the original show to something much darker. For instance, the characters could face more terrifying threats than just Hawk Moth.
The akuma might transform Ladybug's outfit into something dark and sinister, or it could turn it into a costume inspired by a different theme altogether.
Well, Marinette could be like Belle in a sense. She's kind - hearted and intelligent. She might be the one to see past the Beast's exterior, just as she often sees the good in people in the Miraculous Ladybug world. And Chat Noir could be a sort of sidekick to her in this new story, using his cat - like agility to help in the Beast's castle.
Let's say that the Kwamis have some sort of connection to the magic in the ocean. Tikki could have the power to grant Ariel temporary powers on land similar to how she gives Marinette her powers. And Plagg could befriend Sebastian the crab and together they cause some comical chaos while also helping to protect the underwater realm from threats. The characters of Miraculous Ladybug could bring their own unique powers and personalities to the story of The Little Mermaid, adding new layers of adventure and friendship.