The overarching narrative of Naruto's growth would shift. In the original story, the toad contract is part of his journey towards becoming a powerful ninja. Rejecting it means his character arc would take a different path. He might become more independent in his power - seeking, and this could lead to him exploring other hidden aspects of his heritage or discovering new forms of chakra manipulation. It could also open up storylines where he teams up with different characters or groups that he might not have interacted with in the original story due to his focus on the toad - related powers.
His relationships would also be affected. For instance, his connection with Jiraiya, who has a strong link to the toads, might change. Naruto might seek different mentors or allies. This could also impact how he is perceived in the village. Instead of being seen as the one with the potential to master the toad - related powers, he would be seen as an outlier, and this could lead to different reactions from the villagers and other ninja. Moreover, battles would be different. He won't be able to call on the toads for assistance, so he would have to rely more on his own combat skills and strategies, which would rewrite many battle scenes in the story.
Perhaps Naruto has had some negative experiences or premonitions related to the toads. Maybe he saw something in a dream or heard a story that made him hesitant about entering into the contract. Another aspect could be that he wants to break away from the traditional paths of the ninja in his village and forging a new way without the toad contract is part of that.
In a fanfiction where Naruto refuses the toad contract, it would be a major divergence from the original story. His character development would take a different path. Instead of having the toad - related adventures and learning experiences, he could be delving deeper into his own latent abilities. This could lead to him having a more unique and unorthodox fighting style. His interactions with the Hidden Leaf Village and other ninja villages might also change as he is no longer associated with the toads. There could be new rivalries and friendships based on this new path he has chosen, and it could also have an impact on how the other characters view him, as he is breaking away from a long - established tradition within the ninja world.
One possible reason could be that Naruto wants to develop his own unique ninja way without relying on the traditional toad contract. He might feel that it would limit his growth in a sense.
The Hawk Contract could enhance Naruto's speed. Since hawks are known for their swift flight, Naruto might be able to move faster, dodge attacks more easily. For example, he could use the hawk's agility in his own movements during a fight.
In fanfiction, the fox contract can make Naruto more confident. Since he has this special connection with the fox, he might feel like he has an edge over his opponents. This new - found confidence could show in his battles and how he interacts with others.
Naruto's power level would change significantly. He could access Sebastian's demonic powers, which would give him an edge in battles. This would also change how his enemies perceive him. They might be more afraid of him now that he has this new, unknown power source.
The plot could also develop into a conflict with the village. Since Naruto is a key figure in the village, his rejection of his family might have political implications. The village elders might try to interfere and bring Naruto back to the 'right path' which could lead to a power struggle between Naruto and the village leadership.
In a fanfiction where Naruto has leukemia, the plot could take a very different turn. Naruto's usual exuberance and energy would be dampened by his illness. His fights would be more difficult as he would have to deal with the physical weakness brought on by leukemia. The story could focus more on his internal struggle, his fear of dying before achieving his dreams. His friends like Sasuke might have a change of heart seeing Naruto so vulnerable. It could also lead to new alliances in the ninja world as different clans might come together to try and find a cure for Naruto's condition.
Well, it could make Naruto a much darker character. Instead of his usual optimistic self, he might be filled with vengeance. This would change the dynamics of his relationships. His friends would have to deal with this new, brooding Naruto. Also, it might slow down his progress in becoming a stronger ninja as he has to first deal with the trauma of the torture.
In fanfiction, Naruto's contract with Manda can be really interesting. Sometimes, it might deviate from the original story. Writers could create scenarios where Naruto forms the contract under different circumstances, like in a time - travel plot or an alternate universe. Maybe he has to prove himself in a new way to Manda, not just with strength but also with his understanding of the snake's nature.