It's possible that Naruto gives Itachi a custom - made kunai. Naruto knows Itachi is a great ninja, and a special kunai could be a practical and meaningful gift. It could be engraved with some words of respect or friendship.
Naruto might give Itachi some traditional Konoha food as a gift. Since Itachi has been away from the village for a long time, he might miss the taste of home.
Another gift Naruto could give Itachi is a book about the recent history of Konoha. Itachi sacrificed a lot for the village, and he might be interested in knowing how the village has changed and developed during his absence.
In the fanfiction, it could also be a way to bridge the gap between their two clans. Naruto, as someone who wants to bring peace to the ninja world, giving gifts to Itachi can be seen as an attempt to heal the old wounds between the Uchiha clan and the rest of Konoha.
The duck could symbolize peace or friendship. Maybe Naruto gives it to Itachi as a sign of truce or new - found understanding between them.
They could develop a mentor - mentee relationship. Itachi, with his vast knowledge and skills, could guide Naruto. Naruto, in turn, could show Itachi his unwavering spirit, which might even inspire Itachi in some ways.
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.
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.
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.
I'm not sure about a specific one off - hand, but you can check out fanfiction websites like Fanfiction.net or Archive of Our Own. Just search for 'Itachi gives Naruto power' and you'll likely find a bunch of different stories. Some might focus more on the action aspect, while others might explore the emotional side of Itachi's decision to give Naruto power.
A simple plot could be that Itachi entrusts Naruto with his Sharingan because he believes Naruto can use it to bring peace to the ninja world. Naruto, being the kind - hearted person he is, accepts the responsibility. He starts training with Kakashi to understand and master the Sharingan's powers. With the Sharingan, Naruto can anticipate his opponents' moves better and uses this advantage in battles against powerful enemies like Pain.
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.