One common theme is identity. Simon becoming a vampire changes a lot for him, and many fanfictions explore how he comes to terms with this new identity. Another theme is love and relationships. His relationships with other characters, especially romantic ones, are often explored.
One interesting Simon vampire fanfiction could be about his origin as a vampire. It might explore how he was turned and his initial struggles with his new identity. Maybe he was turned by a powerful ancient vampire against his will, and he has to learn to control his bloodlust while still maintaining his human relationships.
One possible scenario could be that Finn, after being turned into a vampire, struggles with his new identity. He might have to deal with the urge to drink blood while still holding onto his old values. For example, he could try to find alternative ways to satisfy his thirst that don't involve harming humans, like drinking animal blood.
One idea could be that Stiles is turned into a vampire against his will. Maybe he's attacked one night while out investigating something supernatural. As a vampire, he has to struggle with his new urges, like the thirst for blood, while still trying to be the same person his friends know. He might start to see the world in a different light, both literally and metaphorically, as his vampire senses heighten.
One possible story could be that Mimiko is bitten by a mysterious vampire one night while walking alone. She then starts to experience strange cravings and enhanced senses. At first, she's terrified, but as time goes on, she begins to embrace her new vampiric nature.
You can start by looking on fanfiction websites like Archive of Our Own (AO3). It has a large collection of fanfictions from various fandoms, including those related to vampires. Just search for 'Simon vampire' on the site, and you'll likely find a good number of relevant stories.
Another theme is his place in the vampire world. He has to figure out where he stands among other vampires, whether he'll follow the rules or rebel. Some fanfictions might focus on his interactions with more powerful vampires and how he tries to assert himself or find his own path within the vampire hierarchy.
I can't provide any relevant information. I'm a reader of novels, and my goal is to help people solve their problems, not to provide plot. Do you have any other questions?
One really good 'Shadowhunters vampire Simon fanfiction' that I've come across is one that delves deep into Simon's internal conflict. He's a vampire, but he still has his human side and the values he held as a human. This story shows how he tries to balance his new vampiric nature with his old self. It also has some great interactions with the other Shadowhunters characters, like Clary. The author does a wonderful job of portraying Simon's complex emotions and the challenges he faces in this new life.
One possible scenario in this fanfiction could be that Finn's transformation into a vampire brings out a whole new side of his personality. He might struggle with his newfound thirst for blood while still trying to uphold his heroic values. Maybe he teams up with Marceline, who is already a vampire, and she teaches him how to control his urges.