Another option could be a completely new character. This character could be an outcast from a small village who discovers the dragon's blood. They then enter the world of the main Naruto story, interacting with the well - known characters. This new character could bring a fresh perspective and new relationships to the Naruto universe, all while dealing with the power and mystery of the dragon's blood.
Sasuke could also be a great choice as the main character in a 'dragon's blood naruto fanfic'. Given his thirst for power and his Sharingan abilities, if he were to obtain the dragon's blood power, it would add a whole new layer to his character. He might use it to seek revenge in a more powerful way or to uncover secrets about his clan that are related to the dragon's blood.
Perhaps an old member of a forgotten clan who was exiled because of his dark blood. He returns with a vendetta against the village that shunned him. He sees Naruto as a symbol of everything he hates and tries to destroy him. The main antagonist could also manipulate other ninja to turn against Naruto by spreading fear about his dark blood.
Might be one of the powerful guards who has a grudge against Naruto for some reason. Maybe he believes Naruto is a threat to the order in the prison and tries to get rid of him secretly.
It could be a character who is jealous of Naruto's new dragon powers. Maybe someone who has always been in competition with Naruto and now feels even more threatened by his enhanced abilities.
It could be a new character created specifically for the fanfiction. Maybe a young ninja who discovers the neglected dragon and forms a bond with it.
Sasuke could also be a great main character in this fanfiction. Given his drive for power, he might be the one to seek out the dragon armor and use it to further his own goals. He could have an interesting journey of learning to control the power of the armor while also dealing with his inner demons.
"I recommend" Blood Dragon Martial God "to you. The main character has a blood dragon pearl and other heaven-defying items. His background is mysterious, and he holds a dragon token. The dragon race reappears on the continent and struggles to become a supreme martial god. I hope you like this fairy's recommendation. Muah ~😗
It could be a long - lost relative of the founders. Maybe a distant cousin of Gryffindor, Ravenclaw, Hufflepuff and Slytherin. This person might have been hidden away for years and now resurfaces.
It might be one of the existing minor characters from the Naruto series who finally gets a chance to shine as Kakashi's apprentice. For example, that one ninja from the background who always admired Kakashi from afar and now has the opportunity to be his student.
Naruto himself could be the main character in a Shinju fanfic. He has always been about finding new ways to bring peace and understanding. His connection to the nine - tails could play an interesting role if he were to interact with the Shinju. Maybe he could try to convince the Shinju that the ninja world has changed and it doesn't need to be a source of fear and destruction.
Sasuke Uchiha could be a great choice as the main character. He already has a complex backstory and a lot of room for character development. His journey from seeking revenge to finding his own path in the Naruto series can be further explored in a fanfic.