Well, there's a fanfic called 'Naruto: Tendo Rikudo's Reawakening'. In this, Naruto discovers ancient secrets of the Tendo Rikudo that have been long forgotten. It has an interesting plot where Naruto uses these new - found knowledge to face powerful enemies. There are also some really good character developments in it.
Naruto is almost always one of the main characters in 'naruto tendo rikudo fanfic' as the stories usually revolve around his connection to the Tendo Rikudo. Sasuke can also be a prominent character as his relationship with Naruto often plays a part in these fanfics.
Yes, in some fanfictions Naruto is depicted as the Rikudo Sennin. Fanfiction writers often like to create alternate storylines where characters take on different roles or powers, and this is one such example.
One implication is the change in power level. Naruto as the Rikudo Sennin would be extremely powerful, which could lead to different battle outcomes. For example, he could easily defeat enemies that were previously tough for him.
The 'naruto heir of the rikudo sennin fanfiction' might be centered around Naruto's growth as the heir. It could include things like Naruto learning the secrets of the Rikudo Sennin, perhaps unlocking some hidden jutsu or knowledge. There could be a focus on the political implications as well, like how different ninja villages react to Naruto being the heir. And it may also involve Naruto's struggle to balance his newfound responsibilities with his own goals and values.
There could be Akane Tendo fanfics out there, but 'lemon' fanfics often contain inappropriate or adult - themed content. If we focus on just regular Akane Tendo fanfics, you might find some really interesting ones that delve into her relationships, her growth as a character, and her adventures. For example, there could be fanfics about her daily life in the Ranma ½ universe that show her dealing with the chaos around her in a new light.
Some fanfictions might focus on the Rikudo Sage's role in the creation of jutsu. There could be new jutsu that he was supposed to have created but never got to use in the original story. Or perhaps fanfictions explore his connection to the chakra system in a more profound way, like how he might have influenced the natural flow of chakra in the world, which could have a huge impact on the abilities of other characters.
The main character is Naruto as he is the heir of the Rikudo Sennin. However, other characters are likely to be involved too. Jiraiya could be a key figure in this fanfiction, considering his connection to Naruto and his knowledge of the past. Additionally, the antagonists in the Naruto world might also be main characters in a sense, as they would oppose Naruto's rise as the heir, either out of jealousy or a desire for power themselves.
You can try Archive of Our Own (AO3). It's a popular platform that has a large collection of fanfics, including those related to Akane Tendo. Just use the search function and type in 'Akane Tendo' and you'll likely get a list of relevant fanfics.
It could show Naruto trying to master the same level of power as Rikudo Sennin. He might struggle with the moral implications of such great power, as Rikudo Sennin had to make difficult choices in his time.