One popular trope is the 'Forbidden Love' aspect. Since Sebastian is a demon and Ciel is a human, their relationship can be seen as something that goes against the natural order. Another is the 'Power Struggle' trope. Ciel may try to assert his authority over Sebastian, but Sebastian's demonic nature gives him an edge in certain situations. 'Soul Bond' is also common. Given their contract and the connection it implies, fanfictions often explore the deeper spiritual and emotional bond that might develop between them.
In Kuroshitsuji Ciel x Sebastian fanfiction, a common trope is the 'Damsel in Distress' reversal. Usually, Ciel is in a position of power as the master, but sometimes fanfictions will put him in a dangerous situation where he needs Sebastian's rescue, highlighting their interdependence. 'Mutual Manipulation' is another trope. They both have their own goals, and they might try to manipulate each other to achieve them. Also, 'Slow - Burn Romance' is popular. Despite their initial master - servant relationship, the idea of a slow - developing romantic connection between them is explored in many fanfictions.
Some fanfictions explore the concept of Sebastian's true nature as a demon and how it affects Ciel. For example, his demonic abilities might both protect and endanger Ciel at the same time. The theme of revenge also comes up a lot. Ciel's quest for revenge and how Sebastian aids him in it can be a central plot. There's also the theme of sacrifice. Whether it's Ciel sacrificing something to keep Sebastian by his side or vice versa, it adds an interesting layer to the stories.
One popular trope is the 'fish out of water' for Sebastian. As he is from a different era or world in a sense, seeing him adjust to modern technology like smartphones and the internet can be really interesting. For example, he might be confused by social media but quickly learn to use it to protect Ciel.
The relationship in 'kuroshitsuji ciel x sebastian fanfic' can be seen as a twisted form of symbiosis. Ciel, having lost so much, uses Sebastian's demonic powers to achieve his goals. Sebastian, on the other hand, patiently waits for Ciel's soul. There are moments of tension and trust between them. For example, in various situations, Ciel has to trust Sebastian to get him out of danger, and Sebastian has to follow Ciel's orders, which sometimes put his own 'demonic code' to the test.
One common theme is the power dynamic. Ciel, as a human, has power over Sebastian in the sense of their contract, but Sebastian's demonic powers far exceed Ciel's. Another theme is loyalty and betrayal. There's always the underlying question of whether Sebastian will truly fulfill the contract or if he might find a way to betray Ciel. Also, the theme of revenge is prominent as Ciel is seeking revenge for his family's death and Sebastian is a key part of that journey.
Well, in Kuroshitsuji fanfiction, Ciel and Sebastian's relationship is a major draw. Ciel is a young boy with a dark past and a strong will for vengeance. Sebastian, being a demon, offers his services to Ciel in exchange for his soul. This sets up a very interesting dynamic. Some fanfictions explore how Ciel's vulnerability and need for protection play into his relationship with Sebastian. Others might focus on Sebastian's demonic nature and how he manages to both serve and manipulate Ciel at times. Their relationship can be full of tension, especially when Ciel's human emotions clash with Sebastian's more demonic view of the world.
Sure. 'A Different Kind of Loyalty' is really good. It explores how Sebastian's loyalty could be more than just what the contract dictates. 'The Darker Side of the Bond' shows a more gritty and real - life view of their relationship. And 'Ciel's Hidden Desires' is interesting as it delves into Ciel's inner thoughts and how they relate to Sebastian.
One popular plotline is the reader being a new addition to the Phantomhive household. This could lead to both Sebastian and Ciel being intrigued by the reader. Another is the reader having some special power or ability that draws Sebastian and Ciel towards them. For example, the reader might be able to see the supernatural more clearly than others, which interests Sebastian as a demon, and Ciel as someone who often deals with the occult in his work. A third plotline could be the reader being from a different world or time, and having to adapt to the Victorian era where Ciel and Sebastian exist, while also dealing with their growing feelings for the two.
There's a fanfic called 'The Meeting of Shadows' which is quite interesting. In this story, Sebastian and Claude are forced to work together on a task by some mysterious force. It shows how they interact when they have a common goal, while still maintaining their enmity. It's a great read if you like exploring their dynamic.
One popular trope is the 'Forbidden Love' trope. Since Ciel is in a rather dark and dangerous world, an OC falling in love with him can be seen as a forbidden thing. Another is the 'Mysterious Newcomer' trope, where the OC arrives at the Phantomhive estate with a hidden agenda or a secret past.
One popular trope is the 'love - hate' relationship. Grell is head - over - heels for Sebastian, but Sebastian is mostly indifferent or even annoyed. Another is the 'rivalry' trope, as they are both strong in their own ways. Grell with his unique scythe skills and Sebastian with his demonic powers.