Emotionally, Ciel would be more detached. He would view relationships more as means to an end. His bond with Sebastian, for instance, would be less about a master - servant dynamic based on the contract for revenge, and more about power and mutual benefit. His view of morality would also change. What was once unacceptable as a human might now be a normal part of his behavior as a demon.
Ciel would likely become more cold - hearted. His experiences as a human, especially the trauma he endured, would be amplified by his new demonic nature. He might lose some of his remaining humanity, such as his sense of compassion.
His intelligence would be sharpened further. Demons are often depicted as cunning, and Ciel already was a very intelligent character. As a demon, he could use his wits in more devious ways. He would be more strategic in achieving his goals, whether it's revenge or something else. His physical abilities would also improve, which would change the way he approaches challenges.
As time goes on, Demon Ciel could develop a more complex understanding of the demon hierarchy. This might lead him to seek more power within the demon world. He could start to manipulate other demons to his advantage, using his wits and newfound demonic abilities. His relationship with Sebastian would also be a key factor in his evolution. If Sebastian were to face a threat, Ciel might have to step up and show a side of himself that is more protective and assertive in the demon realm.
In fanfictions, Ciel's character development can be shown through his growing understanding of the world of demons. As he spends more time with Sebastian, he may become more aware of the true nature of power and the cost of his revenge. His relationship with other characters also plays a role. For example, interactions with his servants might make him more empathetic or, in some cases, more callous as he tries to maintain his position of power.
Female Ciel's development could also be different in terms of relationships. With other male characters, there could be a different kind of tension. For example, in a romantic context, it would be a new aspect as opposed to the original Ciel's more business - like relationships. Also, her friendship with the servants might be deeper in some ways as she might be more in tune with their emotions due to her own experiences of being underestimated because of her gender.
Well, first, you could give her a distinct personality. For example, if Ciel is more reserved and calculating, she could be outgoing and impulsive. This would create an interesting dynamic when they interact. You can also develop her backstory. Say she had a special relationship with a particular character in their childhood that influenced her actions in the present.
Their relationship begins with the contract. Ciel, in his quest for revenge, summons Sebastian. As time passes, Sebastian becomes an essential part of Ciel's life, protecting him from various threats. Ciel starts to rely more and more on Sebastian, and Sebastian is always by his side. They face many challenges together, which deepens their bond, though it remains a master - servant relationship based on the contract.
Ciel might start off seeing Elizabeth as just part of his obligation due to their engagement. But as time goes on in the fanfiction, he could start to notice her inner strength and kindness, which makes him develop deeper feelings for her. For example, if she stands by him during a difficult time, he'll see her in a new light.
Well, 'The Unlikely Bond' is a really good one. It focuses on how Ciel and the demon form an unexpected emotional bond that goes beyond their initial contract. The story is beautifully written and really makes you feel for the characters. 'Ciel's Journey Beyond' is also great. It takes Ciel and the demon on a journey to a far - off land where they encounter strange creatures and new cultures. This fanfiction does a great job of world - building. And 'The Demon's Secret' is a fan favorite. It reveals a long - held secret of the demon that changes the whole dynamic between him and Ciel.
One idea could be a fanfiction where Ciel and the demon, instead of their usual master - servant relationship, become allies in a different realm. They could be on a quest to save a parallel world that is being threatened by a powerful dark force. Another idea is a story where the demon has to protect Ciel from a group of rogue demons who see Ciel as a valuable asset due to his connection with the underworld. Maybe in this fanfiction, Ciel discovers a new power within himself that the demon has to help him control.
One common theme is the exploration of Ciel's relationship with Sebastian as a demon. How their contract changes and how Ciel adapts to his new demonic nature. Another theme is Ciel's struggle for power in the underworld, as he is now a demon. It often involves him facing other powerful demons.
Perhaps in the fanfiction, Ciel discovers some dark secrets about the Phantomhive family or the underworld they are associated with that are so disturbing that he decides to run away. He wants to distance himself from all the evil and corruption, hoping to find a place where he can be free from all the burdens that come with his family name.