Well, one way this could work in a fanfiction is that Naruto could use Yuta's powers to enhance his combat abilities. Yuta has some really unique and powerful cursed energy techniques. Naruto might be able to combine his chakra with Yuta's powers, like using the Rasengan with Yuta's cursed energy for a super - powered attack. It could make for some really interesting battles against tough opponents like Madara or Kaguya.
It's hard to give an exact time as it depends on the manga's plot development. But typically, Yuta Okkotsu shows up when certain events and character arcs lead to his introduction.
If Naruto had Yuta's powers, his fighting style would be drastically different. He'd no longer rely solely on ninjutsu and taijutsu. He could use Yuta's cursed energy to create new types of attacks. For example, he might be able to send out waves of cursed energy like Yuta does, which could catch enemies off guard. This would make him a more versatile fighter and a greater threat to his enemies.
The Harry Potter fandom is great for oc fanfiction. There are so many aspects of the wizarding world to explore, like creating a new student at Hogwarts with unique magical abilities. Another good one is the Star Wars fandom. You can create original characters within the vast galaxy, perhaps a new Jedi or a smuggler in a far - off system. The Marvel Cinematic Universe is also a top choice. You could develop an original superhero or villain with powers related to the existing lore.
One of the top fandoms for fanfiction is the Doctor Who fandom. With its time - traveling and space - exploring premise, the possibilities are endless. You can create new adventures for the Doctor and his companions, or introduce new alien species. The Supernatural fandom is also very popular. There are so many different mythologies and creatures in the show that you can base your fanfiction on. And then there's the Percy Jackson fandom. It combines Greek mythology with modern - day settings. You can write about new quests for demigods, or explore the relationships between different characters from different cabins at Camp Half - Blood.