It could make Sebastian, Ciel's butler, more protective. He might see Elizabeth as a potential weakness for Ciel, or he could also view the relationship as something that could be used to further Ciel's goals. For example, if there are other noble families involved, Sebastian could manipulate the situation based on Ciel and Elizabeth's new - found closeness.
Among Ciel's enemies, the kiss could be seen as a sign of vulnerability. They might target Elizabeth to get to Ciel. This would then force Ciel to take more drastic measures to protect her, and it could also lead to new alliances or enmities as he tries to safeguard his relationship with Elizabeth from those who would seek to harm them.
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.
For Will Turner, if he sees the kiss between Jack and Elizabeth, it would be a huge blow. He loves Elizabeth deeply, and this could lead to a rift between him and Jack. He might see Jack as a traitor, and it would add a lot of tension to their relationship, which was already complex due to their different outlooks on life and love.
In general, yaoi fanfiction about them can make the characters seem more relatable. Their relationship in these stories often involves common human emotions like love, jealousy, and longing. This makes them more like real people rather than just characters in a dark, gothic anime. It can also attract new fans to the original Black Butler series who are interested in exploring these new interpretations of the characters.
One plot idea could be that the kiss is a moment of realization for Ciel. Maybe he has been so focused on his revenge that he has overlooked his feelings for Elizabeth. The kiss makes him question his priorities and whether he can have a normal life with her. For example, he might start to consider giving up some of his more dangerous undertakings in the underworld to protect Elizabeth.
Their relationship can be explored through shared experiences with lemons. For example, they could discover a new lemon - flavored tea together and it becomes 'their' thing. This simple act can show how they bond over something new and different.
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.
For Tomoyo, she might be overjoyed as she has always been supportive of their relationship. She could see this kiss as a sign of their relationship deepening and might start planning more things for them, like new outfits for their future 'dates' in card - capturing adventures.
It can strengthen their relationship. The kiss might be a turning point where they become more than just allies. They start to trust each other on a deeper level and become closer partners in fighting crime.
It could make things a bit awkward at first. Some of the Avengers might be surprised, like Captain America who is more traditional in his views on relationships. Others, like Iron Man, might make jokes about it. But overall, it could also strengthen their bond as a team as they see that Hawkeye and Black Widow are more than just colleagues.
The kiss could change how the TARDIS reacts to them. Since the TARDIS has a sort of sentience, it might sense the change in their relationship and act differently. Maybe it becomes more protective of them or takes them to places that are more conducive to their relationship growth. And other characters like Jack Harkness might tease them about it, adding a new dynamic to their group interactions.