One common theme is his relationships. It could be romantic relationships with other characters in the story's universe. Another theme is his struggle with his own identity, which often makes for an interesting read.
Another theme is his struggle with his identity. Given his character's backstory, fanfic might delve into how he comes to terms with who he is, whether it's related to his powers or his place in the story's world. This can involve internal conflicts and self - discovery.
I'm not sure specifically as I haven't read it. It could be about a character named Harmony Raines having some sort of extraordinary adventure in a fictional world full of magic, mystery or strange creatures.
Alexis might confront Beckett directly. She could say something like 'I think you're cheating on me. What's going on?' This is a very straightforward approach.
I don't know who Alexis is in this story without reading it. But it's likely that Alexis is either the main character or an important figure in the events that unfold in the 'creepy subway' setting.
One popular type might be those that explore Adrian's backstory more deeply. For example, fanfictions could focus on his early days as a vampire and the challenges he faced. Another aspect could be fanfictions that develop his relationships, like his relationship with the main character in different scenarios. There are also ones that might put him in new and exciting adventures outside the main plot of the Bloodbound series.
The theme of loyalty also comes up a lot. His loyalty to his clan or to certain characters in the Bloodbound world is often explored. Fanfics might show him having to make difficult decisions that test his loyalty, like choosing between his loyalty to a friend and the greater good of his vampire community.
Sure. You can start by looking on fanfiction websites like Archive of Our Own. There might be some great Adrian Raines fanfic there that explore different aspects of his character, such as his relationships or his adventures in the fictional world he belongs to.
A lawyer could be an important character. This lawyer takes on Alexis's case, believing in their innocence. The lawyer has to battle a corrupt legal system or powerful opponents who want to see Alexis locked up for good. The fanfic could show the lawyer's strategies and how they build a case in Alexis's favor.