One common theme could be the exploration of Faith's character. The latex catsuit might be used as a symbol of her edginess or her transformation in some stories. It could also be related to themes of power and femininity, as the catsuit can be seen as a form of armor or a statement of confidence.
You could try fanfiction websites like Archive of Our Own (AO3). There's a large collection of Buffy - related fanfics there, and you might be able to find some that feature Faith in a latex catsuit by using the search function and filtering through the results.
One idea could be a story where Buffy and Faith have to go undercover at a high - society event where the latex dress is part of their disguise. They end up having to work together to take down a vampire who is preying on the rich guests.
One common theme could be transformation. The latex clothes might symbolize a new phase or identity for Buffy or Faith. Another theme could be power and control, as latex can be associated with a sense of dominance or allure in the context of the story.
There might be some good ones. You could start by checking out popular fanfic websites like Archive of Our Own. Just search for 'Buffy Faith latex clothes' and you might find some interesting stories that explore different scenarios involving these elements.
Perhaps there's a latex dress that is a key to opening a portal to another dimension. Buffy and Faith both want to control the dress to either keep the portal closed or use it for their own purposes. Their different approaches to this situation create an interesting dynamic in the fanfic.
One great Buffy Faith fanfic is 'Faith's Redemption'. It delves deep into Faith's journey towards redemption. It shows how she overcomes her inner demons and tries to make amends for her past wrongs. The character development is really well - done.
One idea could be a magical competition. They compete to see who can master a new and dangerous spell first. Buffy might use her traditional training and moral compass, while Faith could be more reckless in her approach, which would create a lot of tension.
For Buffy, her friends like Willow and Xander would be likely allies. Willow could use her magic to give Buffy an edge in any magical challenges, and Xander would be there for moral support and to offer his own brand of scrappy help. Giles, too, with his vast knowledge of the supernatural.
Another theme might be related to the power and confidence that the catsuit represents. The character wearing it could be seen as strong and in control, perhaps using it to intimidate opponents or to show their dominance in a particular situation. For example, in a superhero - villain context, a villain in a black latex catsuit might exude an air of danger and unpredictability. And the fanfiction could explore how the heroes deal with this menacing figure.