One idea could be a fanfic where a young ninja discovers a unique way to combine lightning jutsu with other elements like water, creating a new and powerful technique. This could lead to him being sought after by different clans for his knowledge.
In Naruto fanfiction, cheat codes can drastically change the use of jutsu. They might allow a character to instantly master a jutsu that usually takes years of training. For example, a cheat code could give Naruto the ability to use the Rasengan without any training from Jiraiya. It's a fun concept that adds an interesting twist to the Naruto universe.
In fanfiction, the reanimation jutsu might have extended or modified limitations. For instance, in the original, there were clear rules about the caster's control over the reanimated. But in fanfiction, a writer could create a scenario where the reanimated can break free of that control more easily. Also, the source of the sacrifice for the jutsu could be different. In the series, it was usually human sacrifices, but fanfiction might explore using other forms of energy or substances.
Maybe he found some hidden scrolls left by his mother. These scrolls could have contained the details of her jutsu. Naruto, being the curious and determined ninja he is, would have studied these scrolls carefully and learned the jutsu.
Most likely not. 'Lemon' in fanfiction usually indicates something that contains sexual or inappropriate content. Naruto is a popular franchise with a wide fan base including children. Fanfictions should stay within the boundaries of propriety and respect for the original material, and this kind of 'lemon' fanfiction does not seem to meet those criteria.
A third idea for a Naruto poison jutsu fanfic could be a story set in a different era of the Naruto universe. In this time, poison jutsu is a highly respected and feared art. A young ninja, inspired by tales of Naruto, tries to master poison jutsu. However, they face many challenges, including a corrupt master who wants to use the ninja's skills for evil. The young ninja must then decide whether to follow the master or break away and use their skills for the greater good.
A fanfic could also explore Naruto using the Smoke Jutsu for a rescue mission. Suppose some of his friends are trapped in a building surrounded by enemies. Naruto uses the Smoke Jutsu to cover the area. The smoke is so thick that the enemies can't see. Then he sneaks into the building, rescues his friends, and they all escape under the cover of the remaining smoke.
Well, it could be the Uzumaki Chain jutsu. In the Naruto lore, the Uzumaki clan had some unique abilities and the chain jutsu was one of them. His mother Kushina was from the Uzumaki clan, so it's possible that's the jutsu he learned in the fanfiction.
One interesting Naruto secret jutsu in fanfiction could be a time - traveling jutsu. It allows Naruto to go back in time and change certain events in the ninja world. This can lead to all kinds of new storylines and character developments.
In fanfiction, the Lightning Dragon Jutsu can be extremely powerful. It can be depicted as a massive dragon made of pure lightning that can obliterate anything in its path. Another powerful one could be the Lightning God's Wrath, a jutsu that summons a bolt of lightning from the heavens with the power to level mountains.