The theme of loyalty is quite prevalent too. The OC and Killua form a bond where they are loyal to each other. Also, the idea of power and how to control it or use it for good often comes up. As they face various challenges, they have to figure out how to use their powers effectively and not let it corrupt them, all while their relationship grows and changes.
One common theme is adventure. Since the Hunter x Hunter world is full of dangerous and exciting places, fanfics often have the reader and Killua going on quests or exploring new areas. Another theme is friendship. They start to build a strong bond as they face different challenges together.
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 growth. The reader often starts off as a relatively inexperienced character, and through their interactions with Killua, they grow both in terms of their skills as a hunter and in their personal relationships. For example, they might learn how to better control their nen abilities with Killua's help.
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.
Power - seeking is another theme. Many OCs in these fanfics are on a quest to become stronger hunters. They face tough opponents and train hard to improve their skills. This theme is closely related to the overall power - based world of Hunter x Hunter where strength is highly valued.
Another theme is power. In many fanfictions, Killua's sister is portrayed as having unique powers or abilities that she has to learn to control. This could be related to her assassin training or something entirely new. It adds an interesting layer to her character.
One common theme is growth. Biscuit often serves as a mentor to Killua, so a lot of fanfics focus on his growth in strength and character under her guidance.
Sure. One popular 'Hunter x Hunter Killua x OC fanfic' is 'A Bond Beyond Worlds'. It beautifully explores the relationship between Killua and the original character, with great character development and an engaging plot.
Power - up is also a common theme. As the male oc faces stronger opponents, he has to grow in power. This could be through training, finding new weapons or unlocking new levels of his nen abilities. It's exciting to see how the character evolves over time. Another theme is friendship. He forms bonds with other hunters or characters from the 'hunter x hunter' universe, and these relationships help him in his journey.
A common theme is the conflict between their different paths. Killua wants freedom and to make his own choices, while Illumi is bound by the family's rules and expectations. Fanfictions often explore how they deal with this divide.