I'm not sure if there is a specific fanfic with that exact title. Fanfic availability can vary greatly depending on the fandom platforms and the creativity of the writers. You might need to search on popular fanfic websites like Archive of Our Own or Fanfiction.net to see if such a story exists.
One common theme is self - discovery. The OC often discovers new things about themselves while being with Killua. Another theme is friendship evolving into something more. For example, they start as friends or allies and then gradually develop romantic feelings. Also, there's the theme of overcoming differences. Since the OC is not from the original story, they usually have different values or abilities than Killua, and they have to overcome these differences to be together.
Friendship is a very common theme. Gon and Killua have a strong bond, and many fanfictions explore how this friendship grows and endures different trials. For example, they might face a powerful enemy together and their friendship is what helps them get through it.
The common themes include the growth of their relationship. Starting from their initial acquaintance in the series, fanfics show how their relationship evolves into a romantic one. Trust is another big theme. They have to trust each other not only as friends but also as lovers. And many fanfics also touch on the theme of sacrifice. They might be willing to sacrifice for each other's happiness in a more romantic - relationship - based scenario, which is an extension of the selfless friendship they had in the original anime.
The themes usually revolve around family as well. His complex relationship with the Zoldyck family is often explored. Some fanfictions show him trying to reconcile with his family or completely break away. Adventure is another common theme. Since he's a Hunter, fanfictions often send him on exciting adventures, facing new monsters and challenges, which is in line with the spirit of the original 'Hunter x Hunter' series.
One common theme is adventure. Since Killua is from the Hunter x Hunter world which is full of dangerous quests and exploration, many fanfictions involve the reader joining him on his adventures. For example, they might go on a journey to find a rare treasure or explore a mysterious and dangerous place.
One popular 'hunter x hunter gon x killua fanfiction' is 'The Bonds Beyond'. It beautifully explores their deep friendship and the adventures they could have had beyond the main storyline. It has great character development and some really heart - warming moments between Gon and Killua.
If such a fanfic exists, it could potentially have themes of friendship turned into something more, as Killua and Gin might start from a basic acquaintance or even rivalry and develop deeper feelings. Another theme could be adventure, as they might go on some sort of journey together that changes their relationship.
Well, I know a fanfic named 'The Unspoken Bond' in the Gay Gon x Killua category. It delves into the unspoken feelings between them in a really touching way. Additionally, 'Parallel Paths' is quite interesting as it imagines their lives if they had taken different routes while still maintaining their strong connection. There are always new and amazing works popping up in this genre.
One great 'Hunter x Hunter Killua fanfiction' is 'Killua's New Adventure'. It takes Killua on a journey where he discovers a hidden power within himself. Another is 'Killua and Gon's Reunion' which focuses on their friendship after a long separation. There's also 'Killua's Training Days' that delves deep into his training regime and how he overcomes various challenges during it.