He could form a rival - like relationship with Sasuke. Both are highly skilled and have a bit of a dark side. They might constantly compete to prove who's better in combat.
Killua might become friends with Naruto. Naruto's positive attitude and ability to befriend almost anyone could break through Killua's tough exterior. They could learn from each other, with Naruto teaching Killua about the power of friendship in the ninja world, and Killua showing Naruto some of his unique combat techniques.
In a Naruto world fanfic, Killua would bring a whole new dynamic. He has a dark past as an assassin which could either make him a feared or respected figure. His family's training has made him physically and mentally tough. In battles, he could use his electricity - based attacks in creative ways against ninjas. But he would have to learn about things like jutsus and the ninja villages. Also, his relationship with Gon in the HxH world was important for his character development, and in the Naruto world, he might find a similar bond with a fellow shinobi, which could change his perspective on things.
Maybe in the fanfiction, Naruto discovers Killua's world and is in awe of Killua's lightning - based abilities. He then tries to learn from Killua to enhance his own Rasengan or other jutsu. Also, it could involve the two of them teaming up against a common enemy that threatens both their worlds.
Killua's character development in Naruto fanfiction could be quite extensive. He could start as a feared figure due to his assassin skills and strange powers. But as he spends time in the Naruto world, he'd be exposed to new values. He could develop morally, realizing that there are other ways to live than just following the path of an assassin. He could also develop his powers further by combining his nen with chakra - based techniques, and this journey of self - discovery and power - growth could shape him into a more well - rounded and positive character.
He could form some really interesting relationships. He might befriend the underdogs, like the Starks, and use his powers to help them. Or he could have a mentor - like relationship with someone like Tyrion, sharing his wisdom from his own world. He could also have an adversarial relationship with the more power - hungry characters, like Cersei, as his values would likely clash with hers.
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.
The theme of growth is also prevalent. They both start as somewhat naive boys and grow into powerful and more mature individuals. In 'naruto is like killua fanfiction', you might see how they influence each other's growth, for example, Naruto's positive outlook might affect Killua's more cynical view at times, and vice versa.
He would probably form some interesting friendships. He might befriend people who are into martial arts or those with a sense of justice like him. He could also have a mentor - like relationship with some, teaching them about his ninja ways.
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.
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.
Yes, there are some. You can start by looking on fanfiction websites. Some authors might create stories where they draw parallels between Naruto and Killua, perhaps in terms of their growth, their relationships with friends, or their unique abilities.