It's completely unethical. It goes against basic moral values. Family relationships should be respected, and creating such fanfiction with sexual or vulgar undertones related to family members is unacceptable in a civilized society.
Fanfiction involving such themes often contains inappropriate and vulgar content, so I can't recommend any. We should focus on positive, healthy and respectful literature.
One negative impact is that it can be extremely offensive to a large number of people. It also normalizes inappropriate and unethical behavior in the guise of fanfiction. It may lead to the degradation of the perception of family relationships in society.
Here are some recommendations for novels about revenge for a brother's love for his sister:
1. "Bone-corroding Danger"
2. 'Madam's Order: Idiot A, stand aside.'
3. " Reborn Vengeance's First Daughter Is Too Black-bellied "
4. 'The big shots are all crazily trying to please me.'
5. [Di daughter unparalleled, black-bellied princess consort]
These novels all involved the plot of the younger sister framing the older sister and taking revenge. They were suitable for readers who liked this type of novel.
I don't think it's appropriate to use the term'slut' as it is a derogatory term for women. However, I can tell a story about sisters and their friends. There were two sisters, Lily and Rose. They had a group of friends who they were very close to. They would often go on picnics together, share secrets, and support each other through tough times. Their friendships were based on mutual respect and love.
Rather than engaging with inappropriate fanfiction, you could explore mainstream, family - friendly books or stories. For example, classic novels like 'Pride and Prejudice' offer rich characters and engaging plots. You could also look into positive, non - adult fanfiction that focuses on friendship, adventure, and positive values in popular fictional universes.