Well, Buffy can be portrayed as constantly evolving in fanfics, facing new challenges and growing. Willow may be delving deeper into the darker aspects of magic or using her skills for good in unexpected ways. Xander, on the other hand, might be the one who provides the emotional support to the group, and his character development could be centered around his relationships with others.
One common theme is the struggle between good and evil. Buffy and Willow, as the protagonists, are always on the side of good, and the incubus represents an evil force. Another theme is the power dynamics. Willow's magical powers and Buffy's physical strength play important roles in how they face the incubus.
One great fanfic is 'Willow's Ascent'. It delves deep into Willow's journey of self - discovery and her growth as a powerful witch. The story is well - written, with vivid descriptions of her struggles and how she overcomes them. It also has some really interesting interactions with other characters from the Buffyverse.
Fanfics explore their relationships in various ways. Buffy, Willow, and Xander have a long - standing friendship. In some fanfics, this friendship is put to the test when outside forces try to drive them apart. There could be conflicts arising from differences in their personalities, like Buffy's impulsiveness, Willow's studiousness, and Xander's laid - back nature. These differences can create both humorous and tense moments in the fanfics as they navigate their relationships.
Often, Willow fanfics explore her magical abilities in greater depth. For example, some might show her experimenting with new spells that were not in the original series. Also, her relationships, like her friendship with Buffy or her romantic interests, are often expanded upon in interesting ways. In some fanfics, Willow's dark side is explored more thoroughly, which gives a new perspective on her character.
The plot might involve Buffy and Willow dealing with the reactions of their friends. Some might be supportive, like Xander, while others, like Giles, could be more cautious. They could also face a threat from an old enemy who sees the baby as a powerful weapon. As the pregnancy progresses, they grow closer together and learn more about themselves and their relationship.
One popular Buffy Willow incubus fanfic is 'The Dark Encounter'. It has an interesting plot where the incubus character creates a lot of tension in Buffy and Willow's world. Another one could be 'Incubus Intrusion' which focuses on how Willow tries to use her magic to deal with the incubus threat while Buffy is more into the physical combat side of things.
Buffy would likely become even more protective and fierce. Her slayer side would blend with her motherly instincts. Willow would grow in confidence as she uses her magic to care for the baby. She might also become more assertive in protecting their family.
One popular theme is her relationship with other characters. For example, how she interacts with Buffy or Xander in an alternate vampire - filled universe. Another theme is her struggle with her new vampiric nature. Writers often explore how she deals with the thirst for blood and the loss of her humanity.
You can start by looking on fanfiction.net. It has a large collection of Buffy the Vampire Slayer fanfics, and there are likely to be many dedicated to Vampire Willow. Another option is Archive of Our Own (AO3). It has a well - organized tagging system, so you can easily search for Vampire Willow - specific fanfictions there.