He could also develop through facing new threats in the RWBY world. The Grimm are different from his usual opponents in Naruto. Dealing with them might force him to adapt his combat style and in turn, grow as a character. For instance, he might have to rely more on others' skills in a team - based RWBY battle scenario.
One reason could be that he sees something special in Sakura. Maybe he admires her strength or her kind heart, and he doesn't want to lose her to someone else who might not appreciate her as much as he does.
His possessiveness could be seen in his actions towards Sakura. He may be overly protective, like not allowing her to go on dangerous missions alone. He would always want to be the one to accompany her, ensuring her safety at all times. This shows that he doesn't want to share her with any potential threats that could come her way during a mission.
Yes, there might be. The Naruto fandom is vast, and there are many creative fanfictions exploring different relationships and scenarios. You can check popular fanfiction websites like FanFiction.net or Archive of Our Own to see if such a story exists.
In many Naruto fanfictions, the ages of Naruto and Itachi can be quite flexible. Sometimes, authors might change their ages to create different story dynamics. For example, an author could make Itachi younger to explore a different version of his character development, perhaps showing him still in the early stages of his ninja training while dealing with the dark secrets of the Uchiha clan. Naruto's age might also be adjusted, like making him older to be in a more equal power dynamic with Itachi from the start.
Another teammate often included in fanfiction is Kakashi. Some fanfictions might create scenarios where Itachi and Kakashi interact during missions or even in their off - time. It could be interesting to see how their different skills and personalities clash or complement each other. For example, Kakashi's laid - back attitude contrasted with Itachi's more serious and reserved nature.
His character could be developed by showing his adjustment to the Fairy Tail world. He could start off as a loner, but gradually open up to the members. His backstory as a ninja could be explored further in relation to the new environment, like how his past actions affect his new relationships.
Naruto would adapt to Itachi's life in several ways. Socially, he'd have to get used to Itachi's connections and rivalries. For instance, his relationship with Kisame would be different as Naruto. He might try to influence Kisame in a more positive way. Emotionally, he'd have to deal with Itachi's internal struggles. Itachi had a lot of guilt and secrets, and Naruto would have to either come to terms with them or find a way to resolve them. And in terms of combat, he'd practice Itachi's signature moves over and over to make sure he could use them effectively in battle.
Itachi's personality could become more outwardly friendly. In the ninja world, he had to keep many secrets and be aloof. But in the wizarding world as Harry Potter, he might find it easier to let people in. He may also be more assertive in a different way. Instead of silently following orders like in his past life, he could take the lead in situations, using his own judgment based on his past experiences and newfound magical knowledge.