A common theme is family. Given their complex family situation in the original story, fanfictions often explore how Killua and Alluka's relationship affects and is affected by their family. Another theme is protection. Killua is very protective of Alluka, and this is often a central aspect in these fanfictions.
One great 'killua x alluka fanfiction' could be one where they go on a journey to find a cure for a strange illness that has befallen their family. In this fic, Killua's protective nature towards Alluka is highlighted, and their relationship evolves as they face various challenges along the way.
One common theme is Alluka's power and how it affects those around her. Her powers are so unique in the 'Hunter x Hunter' universe that fanfiction often explores how different characters react to it.
In 'killua x gon fanfiction', one characteristic is the exploration of their relationship in different scenarios. It could be in alternate universes where they face new challenges. Also, their friendship is often romanticized to some extent, with the authors delving into the unspoken feelings they might have for each other. Moreover, the fictions usually stay true to their personalities as shown in the original anime, while adding new layers to them.
There's this fanfiction titled 'Alluka's Journey'. In it, Alluka goes on an adventure on her own, away from the main plot of 'Hunter x Hunter'. It delves deep into her powers and how she discovers more about herself while facing various challenges along the way. The story is beautifully written and really captures Alluka's essence.
One popular theme is adventure. Since Gon and Killua are often on adventures in the original story, fanfictions may continue this trend while adding the element of Hisoka's interference. Another theme is the exploration of power dynamics. Hisoka is much more powerful than Gon and Killua at first, so how they grow to face him or interact with him in terms of power is interesting.
The relationships in 'hisoka x gon x killua fanfiction' can vary greatly. Some fanfictions might focus on a possible rivalry between Hisoka and Killua over Gon. Hisoka may see Killua as an obstacle to his 'play' with Gon. Meanwhile, Gon might be oblivious to the full extent of Hisoka's intentions. This creates a dynamic triangle where different emotions like jealousy, friendship, and obsession play out, making for a very engaging read.
One great Gon x Killua x Hisoka fanfiction is 'Unlikely Alliances'. It explores their complex relationships in a unique adventure setting. The story does a wonderful job of showing how Gon's pure heart, Killua's loyalty, and Hisoka's unpredictability interact in different situations.
Friendship is a very common theme. Since Gon and Killua have such a strong bond in the original work, fanfictions often explore different aspects of their friendship, like loyalty and mutual understanding.
Love and loyalty are themes that are often explored as well. It's not always romantic love, but a deep, unwavering loyalty that might exist between them. Some fanfictions show how, despite their differences, they would still be there for each other in difficult situations, like when facing a common enemy or dealing with the challenges within their family.