One idea could be a story where Itachi and Kushina meet in a parallel universe. In this universe, the events of the original Naruto storyline are altered, and they end up on the same side, fighting against a new common enemy. Their unique abilities, Itachi's Sharingan and Kushina's powerful chakra, would make for an interesting combination in battles.
Let's imagine Itachi Uchiha in love with a fellow Uchiha. They grew up together, trained together. Their love was based on a deep understanding of each other's pain and power. But when the Uchiha clan's fate was at stake, Itachi had to make difficult choices. His love for her was strong, but his loyalty to the village made him do things that seemed to shatter their relationship. In the end, his love remained in his heart, a hidden and painful memory.
Imagine a ninja from another land who met Sasuke during a battle. She was a strong and independent fighter. After the battle, she was intrigued by Sasuke's skills and his complex personality. She started to seek him out, and they had many encounters. At first, Sasuke was dismissive, but her persistence and the unique bond they formed over time led to love. Their relationship was not easy, with Sasuke's past always looming, but their love prevailed in the end.
Itachi Uchiha was a complex and tragic character. He was a prodigy in the Uchiha clan. He killed his entire clan except for his younger brother Sasuke, which was a shocking act. But in fact, he did this under orders from the Hidden Leaf Village elders to prevent a coup by the Uchiha clan that would have led to civil war. He lived as a double agent, making himself seem like a villain in Sasuke's eyes so that Sasuke would grow strong enough to kill him and be hailed as a hero, thus protecting the village and Sasuke at the same time.
Sure. There are often crossovers in fanfiction. Writers like to combine different beloved fictional characters. For the 'Harry Potter is Itachi Uchiha' idea, it could be really interesting. For example, Itachi's Sharingan abilities could be compared or integrated with magic in the Harry Potter universe. It might be a bit of a stretch in terms of the two very different settings, but that's the beauty of fanfiction. You can find such fanfictions on websites like Archive of Our Own or FanFiction.net if they exist.
Itachi Uchiha's full story is one of great sacrifice and hidden motives. As a member of the Uchiha clan, he was aware of the growing unrest within the clan against the Hidden Leaf. Instead of allowing a full - blown civil war, he made the difficult choice to kill his clan mates. His actions were misjudged by many, especially Sasuke. Itachi's time in the Akatsuki was also full of intrigue. He constantly had to balance his true loyalty to the Leaf with his role in the criminal organization. And all along, his love for Sasuke was his driving force, even if it seemed like he was cruel to him at times. He wanted Sasuke to become strong enough to take revenge on him and in doing so, free himself from the cycle of hatred.
Another good one is 'Itachi Meets the Avengers'. Here, Itachi's calm and strategic mind makes for some amazing interactions with the Avengers. His abilities seem out of this world to the heroes at first, but they soon realize how useful he can be in battles against powerful foes like Thanos.
Another theme is self - discovery. As Sasuke travels and faces various challenges, he gradually discovers more about himself, his powers, and his place in the ninja world. This is shown through his internal monologues and his reactions to different situations in the novels.
In Sasuke Uchiha lemon fanfics, he may be depicted with a more passionate side when it comes to love and relationships. His usual cold exterior might be softened to show his vulnerability in the context of these often - romantic and physical interactions. However, this is a deviation from his traditional character in the Naruto series where his main goals are related to power and vengeance. These fanfics often explore his character in a more romantic and sometimes sexually - charged way that is not part of the original story.
You should check out 'Naruto & Sasuke: Partners in a New World'. This fanfic takes the two characters and places them in a different, more modern - day like setting while still maintaining their core personalities. It's a fresh take on their relationship. And 'Sasuke's Return to Konoha' is a fanfic that focuses on Sasuke coming back to the village and how he and Naruto work together to improve the village and their standing in it. It has some great dialogue between the two.