She could be a very powerful vampire in her own right. In the fanfiction, her powers might be different from Kaname's. For example, while Kaname has his own set of abilities, she could have the power to manipulate time. This power would make her a very interesting character as she could potentially change the course of events in the Vampire Knight world.
One possible fanfiction could be about Kaname's sister being a hidden protector. She secretly watches over Kaname and Yuki, using her unique powers to keep them safe from the more dangerous vampires in the academy. Maybe she has the ability to foresee danger and intervenes at crucial moments without revealing her true identity.
One possible fanfiction could be where Kaname's sister has a hidden power that she discovers over time. She might struggle with how this power affects her relationship with Kaname and the other vampires in the story. For example, her power could be related to mind - reading, which makes her privy to secrets that she wishes she didn't know.
A plot could be that Kaname's sister discovers a long - lost vampire power that has been dormant in their bloodline. She decides to use this power to bridge the gap between the pureblood vampires and the lower - level vampires. This causes some purebloods to oppose her as they fear a change in the power structure. But she is determined to bring about a new era of peace and coexistence among vampires.
It may represent a moment of defiance. In the world of Vampire Knight, there are many rules and boundaries. Their kiss could be a way of saying they don't care about those restrictions and just want to be together.
In a Vampire Knight fanfiction of Kaname and Zero's wedding, perhaps it would be a very unique and challenging situation. Kaname, being a pureblood vampire, and Zero, a vampire hunter turned vampire, their relationship has always been complex. Their wedding might be a symbol of breaking down the long - standing enmity between vampires and vampire hunters. It could be a grand event in the vampire world, with both sides having to come to terms with this union. Maybe some vampires would oppose it out of pride and tradition, while some might see it as a new beginning for co - existence.
Well, perhaps Yuuki's blood has a special taste or effect on Kaname. It could make him stronger in a unique way, different from other vampires he has bitten before. This could be a significant plot point in the fanfiction as it might attract unwanted attention from other vampires who are envious of Kaname's newfound strength.
One possible plotline could be that Ruka and Kaname start to explore their past relationship more deeply. Maybe there was an event in their past that was left unresolved, like a misunderstanding. They could go on a journey to figure out what really happened, which might involve meeting old friends or foes from their vampire world.
They could face a lot of opposition. The vampire society might see it as a disgrace to their pureblood status as Kaname is marrying a former hunter. And the hunter side could view Zero as a traitor. But their love might be strong enough to overcome all these obstacles. Maybe they'd have a secret ceremony at first, only inviting a few trusted friends like Yuki who understands both of them well.
The plot could be about the child trying to bring about peace between vampires and humans. Using its special connection to both worlds, it could strive to end the long - standing feud. It would face many difficulties along the way, like distrust from both sides, but with determination and the legacy of its parents, it could make a difference.
One way it could develop is through the exploration of their family's reactions. Yuki's adoptive family among the humans might be shocked and concerned. They may not fully understand the implications of a vampire - human hybrid pregnancy. Meanwhile, Kaname's vampire family or clan could have mixed reactions. Some might see it as an opportunity to strengthen their bloodline, while others might fear the unknown consequences. The fanfiction could then revolve around how Yuki and Kaname deal with these family - related issues.