Another aspect could be the world - building within the fanfic. If it's set in the same universe as the original story, it might expand on locations, cultures, or social hierarchies. The author could describe in detail the sister's place in this world, how she interacts with different characters, and what her daily life is like. This would help to create a more immersive experience for the readers.
The fanfic might introduce unique character developments for Ciel's sister. For example, she could have special powers or abilities that are not present in the original story, which would add new layers of plot and drama. Maybe she uses her powers to protect Ciel from unseen threats, or to uncover mysteries within their world.
One interesting aspect could be the exploration of the relationship between Ciel and his sister. It might delve into their shared experiences, secrets, or how they support each other in the fan - created story world.
One interesting aspect could be the exploration of family dynamics. If Ciel has a sister in the fanfic, it might show a different side of his character as an older brother. It could also introduce new plotlines related to protecting or interacting with the sister.
One interesting aspect could be the unique relationships between Ciel and his servants. Maybe it shows how Ciel goes to great lengths to keep them safe, which reveals his loyalty to them despite his often cold exterior.
The exploration of different settings is also a plus. Fanfiction writers might place Alois and Ciel in various fictional scenarios, like a different historical period or a magical realm. This allows for new plotlines and adventures that can be really exciting to read. For example, they could be in a world where magic is more prevalent and they have to rely on each other to survive, which would be a big departure from their normal story.
One idea could be that Ciel's sister was secretly alive all along and has been in hiding, training to avenge the family. She could emerge with unique powers and a strong will, partnering with Sebastian in unexpected ways to take on the enemies that Ciel has faced.
In addition to Ciel and his sister, there could be new characters created specifically for the fanfic. These new characters might be friends or foes of the sister. For example, a mysterious traveler who befriends the sister and helps her in her adventures, or a villain who is after something that the sister possesses.
The most interesting aspect is the clash of different universes. When Ciel crosses over, his Victorian - era upbringing and values meet different cultures and settings. For example, in a crossover with a sci - fi world, his old - fashioned ways are put against advanced technology.
The relationship development is very interesting. Since Ciel has his own dark past and Elizabeth has her own expectations of marriage, seeing how they come together and make it work in fanfiction can be really engaging.
Another theme might be mystery. The sister's existence could be tied to some hidden secrets in the story's universe. It could be about uncovering her past, her connection to certain events or characters, and how she affects Ciel's own journey which is often filled with mystery already.
The best aspect is the exploration of their relationship. Cuddling in these fanfics can show a softer side to their usually complex and often antagonistic relationship.
The character development is often a great aspect. We get to see more of Zero and Ciel's personalities and how they grow together. For example, Ciel might become more confident with Zero's support.