Definitely not. Fanfiction is a realm of creativity where the boundaries are pushed. There are fanfictions that might introduce new Saiyan characters who are the Legendary Super Saiyan. Also, different interpretations of the existing Saiyan lore can lead to scenarios where Goku isn't the sole Legendary Super Saiyan. For example, some fanfictions might play with the idea that the Legendary Super Saiyan is a title that can be passed on or shared among different Saiyans depending on certain conditions.
Well, if Goku was the legendary Super Saiyan in fanfiction, it could completely change the power dynamics in the Dragon Ball universe. There might be new enemies or allies formed based on this twist.
His determination. In fanfiction, Goku's unwavering will to protect his friends and the universe makes him stand out as the Legendary Super Saiyan.
If Goku were the legendary Super Saiyan in fanfic, it could lead to new story arcs and challenges. Maybe he'd face even more powerful villains or have to deal with the weight of his immense power.
It could lead to a completely different power dynamic and story arc. Maybe he'd face challenges earlier or have a quicker rise to fame.
Yes, there are quite a few. You can check out some fanfiction websites like FanFiction.net or Archive of Our Own. Just search for 'legendary super saiyan naruto' and you'll find a variety of stories, some might be about Naruto obtaining the power of a legendary super saiyan in some sort of crossover scenario.
One great Super Saiyan Blue Goku crossover fanfiction is 'Goku in the DC Universe'. It's really exciting to see Goku interact with Superman and other DC heroes. He has to adjust to the different power levels and rules in that universe.
One common theme is growth. Young Goku is constantly growing in power and learning to control his Super Saiyan form.
One more theme is friendship and family. Just like in the original Dragon Ball series, the female Goku in fanfiction also values her relationships. However, her Super Saiyan powers can sometimes put a strain on these relationships. For instance, her need to constantly train and get stronger might conflict with spending time with her family. But in the end, these relationships are usually strengthened through her growth as a Super Saiyan.
Perhaps in the fanfiction, Naruto is sent to a different dimension where he is forced to become a super saiyan to survive. This new power also comes with a new set of challenges, such as dealing with the extreme power fluctuations and the envy of some of the local inhabitants. He then decides to use his super saiyan powers to find a way back to his own world and also to help the people in this new dimension. As he progresses, he discovers secrets about his own past and the connection between his world and this new one that he never knew before.
Well, it depends on what you consider 'good'. There are likely some 'Naruto is a legendary super saiyan fanfiction' works floating around. Some might be really creative, like imagining Naruto with super saiyan powers in the middle of a battle against Akatsuki, while others could be more of a comical take on the idea. But you really have to dig through the fanfiction archives to find the ones that suit your taste.