A common theme is redemption. Since both characters have done things they're not proud of in the original story, many fanfictions explore their journey towards redemption through their relationship with each other.
Another theme is friendship. Despite their differences, they often find a sense of camaraderie in fanfictions. For example, they might support each other through tough times in the ghoul world, like when dealing with other powerful ghouls or the CCG.
The theme of transformation also appears frequently. Their relationship can be a catalyst for personal growth. As they interact more, they change, either becoming more empathetic or learning to control their powers better in the context of the fanfiction stories.
One main theme is friendship. Despite their differences, they often find a connection that could be considered a form of friendship. For example, in many fanfics, they start to understand each other's motives better over time.
One great 'kaneki x nishiki fanfiction' is 'The Bond Beyond the Anomalies'. It delves deep into their complex relationship, exploring how their shared experiences in the ghoul world shape their interactions. The story shows their growth from being rivals to something more nuanced.
Another one is 'Nishiki x Kaneki: A New Chapter'. This fanfic imagines a scenario where after all the chaos in their lives, they start to build a new life together, with a lot of heart - warming interactions and a fresh take on their relationship.
Well, often there's the theme of loyalty and jealousy. The harem members may have different levels of loyalty to Kaneki, and jealousy can arise among them. Also, a theme could be Kaneki's role as a protector. In some fanfictions, he has to protect his harem from threats in the story's world, which adds an element of action and drama to the plot. It's all about how these themes interplay to create an engaging story.
One common theme is the exploration of their complex relationship. Given their different natures, fanfictions often focus on how they come to understand and accept each other. For example, Tsukiyama's initial predatory nature towards Kaneki and how that changes over time.
The theme of forbidden love often comes up as well. In the Tokyo Ghoul universe, the relationship between a ghoul and a human is generally not accepted. So, in Nishiki x Reader fanfictions, there's often the tension of this forbidden love, with the two having to hide their relationship from others, whether it's other ghouls or the CCG.
Self - acceptance is a very prevalent theme. The two Kanekis need to come to terms with their own existence and their relationship with each other. Identity crisis is also common. They both represent different aspects of Kaneki's identity and the fanfic often explores how to reconcile these different identities. Additionally, the theme of power and control can be seen, as they may fight over who gets to be in control in certain situations.
One common theme is survival. Given the nature of their world, they often have to fight to survive together, which strengthens their bond.
Often, there are themes of protection and support. Given the unusual situation of mpreg, Hide might be portrayed as being very protective of Kaneki. And also, themes related to the acceptance within the Tokyo Ghoul world or their own small community could be present. Since it's an unconventional concept, how other characters react to it can be an important part of the story. Additionally, themes of love and sacrifice might be emphasized as they face difficulties together because of the mpreg situation.
One common theme is friendship. Often, the stories start with a simple acquaintance that grows into a deep and meaningful friendship. For example, they might bond over shared hardships or a common goal. Another theme is loyalty. Kaneki and the male reader usually show great loyalty to each other, standing by one another in dangerous situations.