A must - read vampire Buffy fanfiction is 'Shadows of the Night'. This one shows Buffy dealing with a new breed of vampires that are much more cunning and powerful. The author does an excellent job of building the tension throughout the story.
Spike is often paired with Buffy in this type of fanfiction. Since they already had a complex relationship when Buffy was a slayer, it becomes even more interesting when she becomes a vampire. Angel is also a common pairing. Their past relationship and his own experience as a vampire with a soul add a lot of depth to the story.
Definitely Spike. He has his own complex relationship with Buffy. In the fanfiction, he could be a mentor of sorts to Buffy, teaching her how to be a 'better' vampire, or he could see her as a rival in the vampire world. Giles would also be around. He'd be the voice of reason, trying to figure out what caused Buffy's transformation and looking for ways to reverse it while still guiding the Scooby Gang.
Well, I really liked 'Giles: The Early Years'. It gives a great backstory to Giles, showing how he got involved with the Council and his first encounters with the supernatural. 'A Day in the Life of Giles' is a charming short fanfic that just follows Giles through an ordinary day in Sunnydale, but with his unique perspective as a Watcher. There's also 'Giles and the Ancient Artifact' which has an exciting plot involving Giles and a mysterious magical item.
One common theme is identity. Since Dawn becomes a vampire, she has to re - evaluate who she is. Another theme is family. Buffy's reaction to Dawn's new state and how they interact as sisters in this new situation is often explored.
One common theme is identity. Dawn has to figure out who she is as a vampire, different from her human self. Another theme is family. Buffy and the rest of the gang have to deal with Dawn in this new state, which tests their family bonds.
One common theme is the battle between good and evil. Buffy, as the slayer, represents good and the vampires are the evil she has to combat. It's a classic struggle that is central to most of these fanfictions.
One great Buffy fanfiction is 'The Initiative Redux'. It takes the concept of the Initiative from the show and expands on it in a really interesting way. It delves deeper into the experiments and the characters involved in that aspect of the Buffyverse. Another one could be 'Slayer's Bond' which focuses on the relationships between the slayers and how they support each other beyond just fighting vampires and demons. And 'A Different Sunnydale' which reimagines the town and the events in a unique and engaging way.
One common theme is the struggle between good and evil. Since it involves vampires, there's often a battle between the forces of darkness (the vampires) and the forces of good, with Dawn sometimes caught in the middle.
Characteristics could include exploring the more intimate side of the relationships that were only hinted at in the show. For example, if there was a budding romance between two characters in the show, the lemon fanfiction might take it to a more sexual level. However, this can be a controversial area as it may change the tone of the original series. Also, it might focus on the physical attraction between characters like Buffy and Spike or Buffy and Angel, but it's important to note that this is not the main focus of the official Buffy the Vampire Slayer content.