A third common plot element is the power play between them. Ciel uses his position as master to his advantage to make Sebastian jealous. He might give commands that seem to favor another over Sebastian. This not only creates jealousy but also challenges the boundaries of their relationship. The fanfics often explore how far Ciel can push Sebastian before things get out of hand.
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.
Well, 'Jealousy's Stirring' is another good one. Ciel starts to show interest in a new acquaintance, perhaps a bit too much for Sebastian's liking. The fic delves deep into Sebastian's feelings of jealousy, which he tries to hide but fails miserably. It shows a different side of their master - servant bond.
One possible aspect of 'ciel x sebastian jealous fanfic' could be the exploration of complex emotions. In many such fanfics, the jealousy might stem from the unique relationship between Ciel and Sebastian. For example, if there's a new character introduced, Ciel might feel jealous of the attention Sebastian gives to that character. It can add an interesting layer to their relationship which is already full of mystery and power dynamics.
One aspect could be the complex relationship between Sebastian and Ciel in the fanfic. Sebastian's jealousy might stem from his possessive nature over Ciel. He is Ciel's butler but also has a deeper, perhaps unspoken bond. This jealousy could add a new layer of tension to their interactions, for example, when other characters get too close to Ciel. It might lead to some interesting plot developments like Sebastian becoming more protective or overbearing in a way that both confounds and endears him to Ciel.
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.
Well, in non - lemon fanfic, Sebastian is often depicted as a sophisticated, powerful demon who is bound by contract to serve Ciel. Ciel is a young, determined noble with a dark past. But in lemon fanfic which is inappropriate, it may distort their characters in improper ways for the sake of adult - themed content. So it's better to focus on their proper character traits from the original source like Sebastian's loyalty (in a non - inappropriate sense) to the contract and Ciel's intelligence and drive to seek revenge.
Well, a frequent theme is the exploration of their relationship. It could be the development from a simple master - servant relationship to something more profound. Redemption is also a theme sometimes, like Sebastian seeking some form of redemption through his service to Ciel. And the theme of the supernatural is always present, given Sebastian's demonic nature and the dark world they inhabit.
The theme of sacrifice also pops up. Sebastian, being a demon, might have to sacrifice his demonic nature to some extent for Ciel, or Ciel might be willing to sacrifice his own goals or even his soul for Sebastian. This theme makes the relationship between them more intense and deep, and it's often explored in different ways in various ciel and sebastian yaoi fanfics.
A common plot device is the use of misunderstandings. For instance, Ciel might misinterpret Sebastian's possessive actions as overbearing, leading to a rift between them. Then they have to work through their differences to get back to their normal relationship. Another is the introduction of a rival. This rival could be someone who is interested in Ciel, and Sebastian's possessiveness flares up, causing him to take extreme measures to keep Ciel for himself.