One great 'Naruto and Madara Uchiha' fanfiction is 'The Redemption of Madara'. It offers a unique take on how Madara could have been redeemed in the Naruto universe. It has a great plot that keeps you hooked from start to finish.
Madara would have to adapt to the different threats in RWBY, mainly the Grimm. In his world, he was used to fighting other shinobi and clans. The Grimm are a whole new type of enemy. However, his Sharingan would give him an advantage in detecting their movements. He might also try to find a way to use the Grimm's negative energy, similar to how he used negative emotions in his own world to fuel his power.
Yes, there might be such fanfictions out there. The Percy Jackson series and the Naruto world with Madara Uchiha are both quite popular, and fans often like to cross over different universes in fanfiction. It could be really interesting to see how Percy Jackson, with his own set of powers and personality from the Greek mythology - based world, would react to or be a fan of the powerful and complex Madara Uchiha from the Naruto universe.
One popular theme is redemption. Many fanfictions explore the idea of Madara being redeemed through his interactions with Naruto. For example, Naruto's unwavering belief in the good in people might make Madara question his own actions and motives.
Honestly, 'y f n' in fanfic could be a random combination of letters without a widely recognized meaning. Maybe it's a made-up term by the author for a special plot element or character trait.
Naruto would likely be more brooding and introspective. Since the Uchiha are known for their deep emotions and internal conflicts, he would inherit some of that. He might also be more ambitious in terms of power, as Madara was always seeking greater power.
One possible way the storyline could develop is that Naruto would inherit some of Madara's powerful Uchiha abilities, like the Sharingan or even the Rinnegan. This would completely change his power dynamics in the ninja world. He might also face different challenges and enemies, as there could be those who fear his newfound power or connection to Madara.