Sasuke could also be a really engaging character. Maybe in the fanfiction, he has a different path or a new motivation that makes his story more captivating. For example, he could be involved in some sort of mystery related to his clan that wasn't explored in the original. And his interactions with other characters would be different too, adding more depth to his character.
One of the smartest is Sherlock Holmes. He can solve complex mysteries by observing tiny details. Another is Dr. Strange, with his vast knowledge of the mystic arts and his ability to strategize in dangerous situations. And then there's Hermione Granger from the Harry Potter series. She is extremely intelligent, always excelling in her studies and using her knowledge to help her friends out of tricky situations.
Often, original characters created specifically for the fanfiction can be really interesting. For example, an illusionist who can create entire alternate realities within their illusions. They can be very mysterious and add a new layer of intrigue to the Naruto world.
Definitely Naruto's son, Boruto. He has his own set of challenges and goals that make him really interesting. He wants to be his own person rather than just living in Naruto's shadow. Then there's Sarada, Sasuke's daughter. She's strong - willed and determined to prove herself as a great ninja. And Mitsuki, he's an enigma with his unique abilities and mysterious origin.
Shino is often an interesting secondary character in Naruto fanfiction. His ability to control bugs gives a unique aspect to stories. Writers can explore his more introverted nature and how it affects his relationships with other characters. Another one is Rock Lee. His determination and unique fighting style can be the focus. In fanfiction, his story can be expanded on, like his training methods and how he overcomes his limitations.
The question of Chinese mythological characters being the most powerful is difficult to answer because each mythological character has its own unique background and characteristics. Their combat power may vary according to time, place, storyline and other factors. However, in Chinese mythology, there were some characters who were widely regarded as very powerful warriors, such as Sun Wukong, Ultraman, Guan Yu, etc. Sun Wukong was one of the most famous heroes in ancient Chinese mythology. He had the seventy-two transformations and the somersault cloud. He could transform into various forms and was extremely powerful. Ultraman was a Japanese superhuman warrior who had superhuman strength and speed to fight against the gods. Guan Yu, on the other hand, was a famous general in ancient China. He had great martial arts courage and high intelligence, and could launch powerful martial arts and intelligent strategies. There were many intelligent people in Chinese mythology, such as Zhuge Liang, King Wen of Zhou, Confucius, etc. In many stories, these characters showed amazing intelligence and wisdom, thinking and devising excellent strategies to win.
Sasuke is really interesting to pair with Naruto. Their complex relationship in the original series gives a lot of room for fanfic writers to explore different emotions and storylines. Kakashi is also great. He can act as a mentor or a partner in different adventures with Naruto.
The Godaime Hokage herself is of course very interesting. Her unique abilities and leadership style make her stand out. Then there's often a new generation of ninjas who interact with her. They bring fresh perspectives and challenges. Also, some fanfictions might introduce new villains specifically designed to oppose her, and these villains can be really interesting with their own motives and powers.
The Sage of Six Paths could be included. As he is the originator of many ninja powers, his connection to Amaterasu could be explored. Maybe he had a hand in creating or containing the power. His presence in the fanfiction would raise the stakes and give a more epic feel. Additionally, Hinata could be in the story. Her love for Naruto could play a role, for example, if Naruto is in danger because of Amaterasu, Hinata could try to save him in her own way.
Sasuke is a great character to include. His cool and brooding personality can create interesting dynamics in crossovers. For example, if he crosses over into the world of Attack on Titan, his skills as a ninja would be put to the test against the Titans. Another interesting character is Kakashi. His laid - back yet highly skilled nature can add humor and action to crossovers. He could be a great addition in a crossover with the world of Inuyasha, sharing his knowledge of combat and jutsu.
One of the most interesting characters could be a new character created specifically for the fanfiction with a unique bloodline ability, like the power to create illusions so real that they can physically harm opponents. Another interesting character could be an existing character from the Naruto series whose bloodline is explored in more depth, such as Rock Lee if he were to have a secret bloodline that enhances his taijutsu in unexpected ways. And there's also the possibility of a villainous character with a bloodline that gives them the ability to steal other people's chakra.