One common theme is redemption. Since Nooroo is often forced to do Hawkmoth's bidding, many fanfictions focus on him trying to make up for his actions.
Maybe the Wolf Kwami has a special power that is different from the other Kwamis. A new villain wants to steal this power for their own evil plans. The story could focus on Ladybug and Chat Noir protecting the Wolf Kwami and its power. This would involve a lot of action and adventure scenes.
Let's make a Kwami named Luma. Luma could be a Kwami related to stardust. Its Miraculous could be a star - shaped hairpin. The superhero with this Miraculous would be able to fly faster than normal superheroes, and also have the ability to create a shield made of stardust that can protect from most attacks.
Well, this kind of fanfiction could start with Marinette making a mistake while using the Miraculous. Then she finds herself in the form of a Kwami. She might be really tiny and have to find ways to get around. She could hitch rides on people's shoulders or use her small size to her advantage when it comes to spying on Hawk Moth. And she would definitely have to deal with the fact that she can't just transform back into her normal self right away, leading to all sorts of comical and tense situations.
Another way is to have the Kwami OC interact with the existing Kwamis in the Miraculous Ladybug universe. If your Kwami OC is Ember, which has the power of fire, it could meet Tikki and Plagg. They could have a conversation about how their powers are different yet related. This kind of interaction can add depth to your fanfiction.
One common theme is friendship. The Bee Kwami often forms strong bonds with other characters, whether it's Ladybug, Cat Noir or other Kwamis. It shows how these friendships help in facing challenges in the Miraculous world.
In a fanfiction, the Dragon Kwami could be a bit of an enigma. It might have some secrets that not even the other Kwamis are fully aware of. It could be silent most of the time, observing everything around it. But when it does speak, it says things that are very profound and thought - provoking. This kind of characterization would make the Dragon Kwami more mysterious and interesting in the story.
First, know the Miraculous Ladybug universe well. Understand the existing characters, their relationships, and the rules of the Miraculous. For the Wolf Kwami, think about what kind of powers it might have. Then, create an interesting plot. It could be a story of the Wolf Kwami's origin or how it affects the main characters in a new situation.
One popular theme is the exploration of the Kwamis' personalities. For example, Tikki's positive and guiding nature can be delved into more deeply. Another theme is the relationship between the Kwamis and their holders. How they interact, communicate, and support each other during battles and in daily life. Also, some fanfictions focus on the origin of the Kwamis, creating backstories that are not fully explored in the original series. This could include where they came from before they were associated with the Miraculous jewels and how they came to be part of the whole Miraculous system.