Another plot could be that Damon becomes human again to be with a human he loves. But once he is human, he realizes that the world he thought he knew as a vampire is very different. He has to start from scratch in building relationships, getting a job, and learning how to live without his vampire powers. He also has to face the jealousy and hatred from some vampires who see his transformation as a betrayal.
A plot could revolve around Damon trying to make amends for his past vampire deeds as a human. He could start by helping the victims of his previous vampire attacks or their families. Also, his love life would change. If he was in a relationship with a vampire or a human before, now as a human, new dynamics would emerge. He might worry about being too weak to protect his loved ones.
A powerful witch could be the antagonist. She might have been the one who turned Damon human again against his will, and now she has some sinister plan for him. For example, she wants to use his new human form to perform some dark magic ritual that requires a human with a vampire past.
Perhaps there is a scientific experiment gone wrong that turns Sans into a human. He then has to hide his identity from the other monsters while he tries to find a way to reverse the process. In the meantime, he experiences human sensations like hunger and fatigue for the first time, which makes for some comical and also poignant moments in the fanfiction.
One idea could be that Godzilla, as a human, has to hide his true identity while trying to understand human emotions. He might struggle with the concept of love and friendship, which are very different from his previous existence.
A cool concept for 'human becomes twilight fanfiction' is a human who gets transported into the Twilight universe. This person could try to change the story's events. Maybe they befriend Bella and try to prevent some of the dangerous situations she gets into. Or they could end up falling in love with a minor character and create a whole new sub - plot. It could also be that they are turned into a hybrid of a vampire and a werewolf, which is a unique situation not really explored in the original series.
One idea could be that they face challenges from the supernatural community because of their union. Maybe other vampires are jealous or see it as a threat to the vampire hierarchy.
The baby could also be a way to explore the more human side of Damon. He has always been a bit of a bad boy, but with a baby, he might become more nurturing. Caroline, on the other hand, could be the strict but loving mother. Their different parenting styles could lead to some humorous and heartwarming moments in the fanfiction.
One idea could be that Damon and Bella meet in a casino in Vegas. Damon, with his charm, tries to win Bella over in a game of poker. Another could be they both get involved in a mystery related to an old Vegas hotel, and they have to work together to solve it.
One idea could be that Damon is initially terrified of becoming a father but then gradually embraces the role as he sees Elena's excitement. Another could be that they face threats from the supernatural world because of the unborn child, like vampires or witches who want to use the baby's power. Maybe there's a prophecy about their child that causes all kinds of chaos in their lives.
Another plot could be centered around the baby's upbringing in a world full of supernatural beings. Damon and Elena might struggle with how to raise the baby in a way that it can fit into both the human and supernatural worlds. They could face challenges like finding the right school or dealing with other vampires who might not be so accepting of a half - vampire baby. Maybe they would have to move to a new place to keep the baby safe.