One idea could be to create a Shinigami OC who is a bit of an outcast among the Shinigami. Maybe this OC doesn't like the idea of just writing names in the Death Note and wants to find a more 'humane' way to deal with humans, which could lead to all sorts of interesting conflicts with other Shinigami. For example, they might try to influence humans in a positive way before their time is up instead of just causing their death.
First, consider their backstory. A Shinigami's past can greatly influence their present behavior. For example, if they were once a human who had a tragic end, it could shape their view on death and how they interact with living beings. Second, think about their personality traits. Are they cold and calculating like most Shinigami, or do they have a softer side? Maybe they're curious about humans in a way that other Shinigami aren't. Third, their relationships with other characters matter. Do they have a rival among the Shinigami? Or perhaps a mentor? These relationships can add depth to the character.
It focuses on the story of L's early days and how he solves cases. In this novel, we see L's unique detective methods and his battle of wits against various criminals.
One possible fanfiction could be where Light is in the hospital due to an unexpected illness. Maybe he uses this time to plot his next moves in the Death Note world without arousing too much suspicion. He could be pretending to be weaker than he actually is while observing the people around him, looking for potential Kira supporters or enemies among the hospital staff and patients.
A 'death note light x oc fanfiction' often involves creating an original character (OC) and pairing them with Light from 'Death Note'. It can explore unique relationships and scenarios that didn't exist in the original story. For example, the OC might be someone who discovers Light's secret early on and has to decide whether to support him or expose him.