One way to develop their relationship uniquely is to have a magical object that links their minds. This would mean that they constantly share thoughts and feelings, whether they like it or not. At first, they fight against this connection, but as time goes on, they learn to use it to their advantage and it deepens their relationship. For example, Ventus might use it to reach out to Vanitas when he is in danger, and Vanitas might start to rely on Ventus's positive emotions to fight against his own darkness.
In Kingdom Hearts fanfiction, the relationship between Vanitas and an OC (Original Character) can be really complex. It might start with conflict as Vanitas is often a rather dark and brooding character. The OC could be initially drawn into his world by accident or perhaps be a part of some grander scheme. For example, the OC might have a special power that Vanitas wants to either use or destroy.
One unique way to develop their relationship is by having them switch roles. Let female Riku take on Sora's typical role of being the more impulsive one, while Sora becomes more cautious like Riku usually is. This role - reversal can lead to some comical situations at first, but as they adapt, they learn more about each other and grow closer in the process. It can also make them see their own strengths and weaknesses in a new light.
One good one could be 'The Bond Beyond Darkness'. It really delves into the complex relationship between Ventus and Vanitas. It shows how their connection is more than just their opposing natures.
Perhaps a fanfiction where Ventus has a premonition of a great danger that only he and Vanitas can prevent together. As they journey to stop it, they gradually form an unexpected bond. They learn that their connection is deeper than they initially thought, and this realization changes their relationship throughout the story.
The appeal lies in their complex relationship. Ventus is the light and Vanitas the dark, so it's interesting to see how they interact.
It could develop into a strong friendship. They would likely bond over their shared experiences and the fact that they are both keyblade wielders. They might start training together to become even better at using their keyblades.
They could start a secret project together, like building a super - advanced gadget. As they work on it, they share their dreams, fears, and secrets. This shared experience outside of their regular hero/vigilante work can bring them closer.
A really unique way to develop their relationship could be through a time - travel plot. Maybe they both get sent back to a different era in the Upper East Side's history. There, they have to rely on each other to survive and adapt. This would not only test their relationship but also give them a chance to see how their families' legacies have shaped who they are today. They could come back to the present with a much stronger bond.
First, make sure their personalities complement each other. Ventus is kind - hearted and brave. So, if the OC is more cautious and analytical, they can balance each other out. For example, Ventus might rush into a fight, and the OC can stop him and think of a better strategy.
Their relationship can be developed through shared battles. When they fight side by side against strong enemies, they'll learn to trust each other more.