Hisoka is still alive in the manga. The storylines haven't led to his death yet. Maybe there'll be developments in the future, but for now, he's kicking.
In Hisoka x OC fanfiction, the OC often serves as a way to insert new perspectives into the story. The author can give the OC special abilities or a unique personality that either complements or clashes with Hisoka. If the OC has a strong sense of justice, for instance, it would be in direct contrast to Hisoka's more self - serving nature. This contrast can drive the plot forward, creating conflict and resolution. Also, the development of their relationship can be a major focus. It could start from a simple encounter and gradually evolve into a complex bond, whether it's a friendship, a rivalry, or something more romantic. The key is to make the relationship believable within the context of the original story's universe.
Common themes in 'Hisoka and pregnant' fanfiction often revolve around the relationship changes. Hisoka's relationships with other characters, especially the one who is pregnant, will likely be a central focus. There could be themes of love, or at least an unusual form of attachment developing. Also, the theme of facing the consequences of one's actions might be present, as the pregnancy is a significant event that will have far - reaching impacts on the story's world and characters. Additionally, the struggle between Hisoka's old ways and the new responsibilities that come with the pregnancy can make for an interesting narrative.
In Hisoka x Illumi yaoi fanfictions, the attraction between them could be based on mutual respect for each other's power. Hisoka is always seeking strong opponents, and Illumi is a very powerful assassin. Their interactions in the original work provide a rich source of material for fanfiction writers to develop romantic or at least deeply emotional relationships between them.
One great Hisoka x Reader fanfiction is 'Hisoka's Obsession'. It delves deep into the complex relationship between Hisoka and the reader, with a lot of psychological exploration. Another one is 'A Dance with Hisoka' which has a really interesting plot where the reader character is involved in Hisoka's dangerous world of battles and power plays. And 'Hisoka's Secret Admirer' is also a good read as it shows a more tender side of Hisoka towards the reader in a very unique way.