A common theme is the exploration of the unknown. Since Mephisto is often associated with mystery, fan fictions usually involve the reader character delving into Mephisto's dark and magical world.
Well, it depends on the writers' imagination and the direction of the story. Sometimes characters take unexpected paths, so Loki ending up there isn't out of the question.
One great piece of mephisto x reader fan fiction is 'Mephisto's Encounter' which has an interesting plot where the reader character gets involved in Mephisto's mysterious world. It's full of vivid descriptions and engaging dialogues.
Sick uke yaoi manga often features vulnerable and physically or emotionally unwell male characters in romantic relationships. The storylines can be intense and explore complex emotions.
If the manga yaoi uke is sick, it could be a chance for the seme to show care and support. Maybe they take them to the doctor or nurse them back to health at home with lots of love and tenderness.
Typically, the uke is the main focus. They are usually shown as physically or emotionally weaker compared to others in the story. The bully is another key character. They can range from a one - dimensional antagonist who just likes to cause harm to a more multi - faceted character with a backstory explaining their bullying behavior. A protector type of character is also common. This could be someone who witnesses the bullying and decides to step in to protect the uke. And there may be a group of peers. They can either be part of the problem by joining in on the bullying or part of the solution by standing up for the uke.
One common theme is romance. Often, Naruto is paired with another character in a romantic relationship where he is the uke. Another theme is self - discovery, as Naruto navigates his new role and the feelings that come with it.