I think another important theme is sacrifice. Itachi sacrificed his reputation, his relationship with his family and his own life in a way. He lived in the shadows, in this 'darkness' of secrecy and lies, all for the 'light' which was the safety and future of the Hidden Leaf Village. His story in the novel is a complex exploration of these ideas of sacrifice, light and darkness.
In Itachi yaoi fanfiction, Itachi is often depicted as a complex and mysterious character. He is usually highly intelligent and powerful, which makes him an alluring figure in romantic or relationship - based stories. His loyalty, whether it be to his family, his village, or his love interest in the yaoi context, is also a common characteristic explored.
He would likely be adapted as a very powerful and mysterious character. His skills in the Naruto universe would translate into some sort of special magical abilities in the Harry Potter world. For example, his Sharingan could be like a super - powerful magical eye that gives him unique insights.
Sasuke is often paired with Itachi in these fanfictions. Since they are brothers, when Itachi time - travels, his interactions with Sasuke are crucial. Sasuke might be at a different stage in his life, and Itachi could try to influence his development. Another common character is Naruto. Naruto's ideals of friendship and peace could contrast with Itachi's more complex and tragic view. Their interactions could lead to interesting plot developments.
Sasuke is often paired with Itachi in these fanfictions. Their complex relationship from the original Naruto series can be explored in new ways in another world. For example, they might be on a mission together in a world full of unknown dangers. Another popular character to be paired with Itachi is Naruto. Their different outlooks on life and friendship can create interesting dynamics, especially when they are in a strange new world where they have to rely on each other more than ever. Shisui could also be paired with Itachi. Since they were friends in the original story, in the fanfiction, they could be reunited in another world and face challenges together, perhaps against a new and powerful enemy.
Well, there might be characters from their clan. Since Itachi is from the Uchiha clan, other Uchiha members could play significant roles. They could be elders or other young Uchiha who are involved in the clan's affairs and in turn, affect Itachi and Izumi's story.
Itachi would probably be very calm and composed. He might see Sarada as a symbol of the new generation of ninjas in the village. He could be gentle with her, perhaps sensing her potential and her desire to grow as a ninja.
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.