Gon in fanfiction can be very single - minded in his pursuit of goals, just like in the original. He might be a bit more naive at times, which can lead to interesting plot twists. Killua is often portrayed as having a complex emotional side. He struggles with his past as an assassin and his loyalty to Gon. His cool exterior may crack in some fanfictions, showing his true feelings.
I recommend "The Struggle of Leisurely in the End of the World" to you. This is a book with family, friendship, and love as its theme. It tells the story of struggling to survive in the end of the world. The protagonist, Zou Yingying, only hoped to be with her family and live her life in peace. At the same time, she was actively fighting. This novel was heartwarming, touching, and fascinating. It was really worth reading. I hope you like this fairy's recommendation. Muah ~😗
Yes, there are likely some fanfictions out there with such a concept. Fanfiction writers often come up with creative crossovers. You can try searching on popular fanfiction websites like Archive of Our Own or Fanfiction.net.
Another option is to join 'Hunter x Hunter' fan communities. These could be on social media platforms like Reddit or Discord. Members of these communities often recommend good fanfictions. They can give you direct links or at least point you in the right direction to find family - friendly 'Killua x Gon' stories.
I think Midoriya could be his best friend. Midoriya is kind - hearted and always looking to learn, which would appeal to Killua. They could bond over their shared desire to become stronger and protect others.
Often, they show a deeper level of commitment. The mpreg forces them to rely on each other more. For example, Gon might become more protective of Killua during the pregnancy.
As I mentioned before, 'lemon' implies adult content which is not suitable for discussion. So, I can't really talk about the characteristics of such fanfics.