Fanfiction.net could also be a good place to look. There are many users who contribute different types of fanfictions. However, the quality can vary. You need to look through the tags related to Gene and Zane to narrow down your search and find the ones that might interest you.
One possibility is that it could be an ancient genetic trait passed down from a long - forgotten clan in the Naruto universe. Maybe this clan had some unique powers that were lost over time, and the X gene is a remnant of those powers.
Overcoming obstacles is also quite prevalent. It could be external factors like enemies or internal ones like their own insecurities. For instance, in many fanfics, they have to deal with people who don't approve of their relationship, be it as friends or something more. And this makes for an interesting plot as they fight against such odds.
One great 'Ninjago Jay x Zane Fanfiction' is 'Electric and Ice'. It beautifully explores their friendship evolving into something more. The author does a wonderful job of portraying Jay's energetic nature against Zane's calm demeanor, and how they complement each other. It has some really sweet moments that make you root for their relationship.
One common theme is the idea of redemption. Zane often has a bit of a troubled past in the series, and in fanfics, his relationship with Aphmau can be a path towards redemption. Another theme is the discovery of love. They might start off as just friends or even enemies, and then gradually realize their feelings for each other.
A strong plot is another characteristic. It could be an adventure that the two embark on together, or a story about how they overcome differences. In some cases, it might be a mystery that they solve side by side. The plot should be engaging and keep the reader interested.
It's possible that the X gene would also affect Naruto's physical abilities. He could become faster, stronger, and more durable. His stamina might increase significantly, enabling him to fight for longer periods without getting tired. This would make him an even more formidable ninja, especially in long - drawn - out battles against tough opponents.
One common theme is friendship. Gene and Louise might be shown as having a deepening friendship through various adventures. Another theme could be family - like relationships, where they support each other like siblings.
One common theme is redemption. Gene often has a past that he needs to atone for, and Aphmau is a part of that journey. Another is the development of an unexpected relationship. They might start as enemies or strangers and then grow closer. Trust is also a big theme as Gene may not be the most trustworthy character at first, but Aphmau helps him earn it.