In some fanfictions, it could be through a special jutsu or ritual. Maybe Itachi, before his death, transferred his Sharingan to Naruto in a unique way, perhaps using a forbidden technique that was known only to a few in the Uchiha clan.
Definitely include Obito. His complex relationship with the Uchiha clan and his own history with the Anbu - like Akatsuki could create some interesting plot twists. Additionally, Kurenai could be added. She could be involved in a mission where she has to work with Itachi and Naruto. Her genjutsu skills might come in handy during a crucial part of the story. And don't forget about Rock Lee. His determination and unique fighting style could add some action - packed scenes to the fanfiction, especially if he gets involved in a mission with Itachi and Naruto.
Naruto's perspective on the ninja world could change. With the Rinnegan, he would see things in a different light, both literally and metaphorically. He might have to deal with new enemies who are attracted to his new power or new responsibilities that come with such a powerful dojutsu. His relationships with his friends and allies could also be affected as they may view him differently now that he has this extremely powerful ability.
One interesting aspect of Naruto Rule 63 Itachi fanfiction could be exploring Itachi's character from a different gender perspective. In these fanfictions, Itachi might have different relationships with other characters. For example, his bond with Sasuke could be portrayed in a new light, perhaps with more emotional nuances due to the gender - swap. Also, the way he approaches his mission and his loyalty to the village could be re - examined through this new lens.
The original Naruto storyline focuses on Naruto's growth, his pursuit of becoming Hokage, and his relationships within the ninja world in a more traditional sense. However, in 'itachi cheats on naruto fanfiction', it takes a very different turn. It adds a whole new layer of drama and conflict that is not present in the original. Itachi's character is also distorted in a way as it gives him a new, rather uncharacteristic behavior of 'cheating' which changes the dynamics of how we perceive him and his connection to Naruto.
Their relationship could be developed through a series of flashbacks. For instance, Itachi could recall moments from Naruto's childhood that he observed while in the ANBU. These memories could make him see Naruto in a new light. Meanwhile, Naruto could learn about Itachi's past and the sacrifices he made. This exchange of knowledge could build a bond between them based on empathy and respect. In addition, they could train together in secret, with Itachi teaching Naruto some of his ANBU skills, which would also strengthen their relationship.
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.
They could develop a mentor - mentee relationship. Itachi uses his knowledge of the Sharingan to teach Naruto new combat techniques. As they train together, they bond over their shared experiences of loss and their desire to protect the people they care about. Naruto might also help Itachi come to terms with his past actions and find some peace within himself.