A major theme is the duality of their relationship. On one hand, they have a strict master - servant relationship as per the contract. On the other hand, there are hints of a deeper emotional connection. There are also themes related to the dark and mysterious world they inhabit. The fanfics often explore the dark magic, the underworld, and how Ciel and Sebastian navigate through it all while dealing with their relationship.
One common theme is the power imbalance. Sebastian is a powerful demon, and Ciel is a young, mortal master. This creates a lot of tension and interesting situations where Ciel is constantly trying to hold his own against Sebastian. Another theme is loyalty and its limits. Sebastian is bound by a contract, but his true motives are often questioned.
The theme of sacrifice also shows up a lot. Ciel may sacrifice his own humanity in order to achieve his goals, and Sebastian may sacrifice his own freedom in a way by being bound to Ciel. And there's always the theme of the supernatural, with Sebastian being a demon and all the dark magic and otherworldly elements that come with that in the fanfics.
One great 'Black Butler Sebastian x Ciel fanfic' is 'A Bond Beyond Servitude'. It beautifully explores the complex relationship between Sebastian and Ciel. The author delves deep into their characters, showing how their fates are intertwined. Sebastian's loyalty to Ciel, which is tinged with his own demonic motives, is portrayed in an interesting way. It also has some really well - written dialogue that stays true to the original anime's tone.
In 'Black Butler Sebastian x Claude fanfic', one of the main themes is the exploration of their complex personalities. They are both mysterious and have their own motives. This is often explored in detail. Another theme is the idea of loyalty. Their loyalty to their masters can create interesting conflicts and situations. And a third common theme is the concept of the supernatural world they inhabit. The rules and hierarchies of the demon world are often part of the stories.
The theme of mystery is quite prevalent. There are always secrets between Sebastian and Ciel. Sebastian's true nature as a demon and his long - term plans are often a mystery. In fanfiction, this mystery is sometimes deepened or resolved in different ways. And the theme of sacrifice can also be found. Ciel might have to sacrifice parts of his humanity to achieve his goals with Sebastian by his side, and Sebastian may also have to sacrifice some of his demonic desires for the sake of the contract.
Some fanfictions revolve around the theme of trust. In the Black Butler universe, trust is a very fragile thing between Sebastian and Ciel. Fanfiction writers love to explore how this trust can be built, broken, and rebuilt. Another theme is the exploration of their individual traumas. Ciel's past trauma of losing his family and Sebastian's existence as a demon with his own kind of 'demonic trauma' can be the focus. Writers might show how they deal with these traumas in relation to each other. Additionally, the theme of identity is also present. Ciel's identity as the Earl and his true self, and Sebastian's identity as a demon but also his role as Ciel's servant are often explored in different ways in these fanfictions.
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.
A common theme is possessiveness. Since Ciel and Sebastian have a rather special bond, any threat to that bond can trigger possessiveness which is often expressed as jealousy. Another theme could be the fear of loss. Ciel, having lost so much already, might be terrified of losing Sebastian to someone else, and this fear can manifest as jealousy.
In these fanfics, a recurring theme is the power dynamic. With Sebastian being jealous, it can either strengthen or weaken the power he has over Ciel. If he becomes over - protective due to jealousy, Ciel might gain some power in the relationship as Sebastian's actions are more driven by emotion. Another theme is the idea of loyalty. Sebastian's jealousy could be seen as an extreme form of loyalty, not wanting anyone else to have what he considers his (in relation to Ciel). And of course, the theme of love, in a very complex and often unspoken way, is also quite common as the jealousy is often a sign of deeper feelings.
Another theme is the power dynamic between them. Ciel is the master, but Sebastian has his own power. Fanfics play with this dynamic, sometimes showing Ciel trying to assert more control or Sebastian subtly influencing Ciel. For example, in some fanfics, Ciel may try to break free from Sebastian's influence while still relying on him. It makes for very interesting reads.
One common theme is loyalty. Finny's unwavering loyalty to Ciel is often a central aspect. Another theme could be protection. Finny protecting Ciel from various threats, be it other supernatural beings or human enemies. Also, growth is a theme. Ciel might grow as a person because of his interactions with Finny, learning about emotions like trust and kindness that he may not have fully understood before.