It's not a common occurrence. Usually, Amaterasu is associated with specific characters in certain fictional settings. Natsu and Sasuke aren't typically granted that ability. But in creative reimaginings or crossovers, anything can happen.
Perhaps Sasuke uses Sakura to get closer to some information. He might know that Sakura has connections or knowledge that can help him in his quest for revenge or for protecting the village. So he uses her in a strategic way while she is initially unaware of his motives. As the story progresses, their relationship could develop in complex ways.
One interesting story could be where Sasuke uses Sakura's medical skills to his advantage during a difficult battle. He might rely on her to heal his wounds quickly so he can continue fighting.
Well, I don't have a particular 'sasuke uses sakura fanfic' at hand. However, when looking for such a fanfic, you should look for Naruto - related fanfic sections. You could also join Naruto fan communities on social media platforms and ask the members if they know of any good ones.
There's a great one called 'Sasuke's Utilization of Sakura'. Here, Sasuke uses Sakura's physical strength. Sakura has trained hard and become quite powerful. Sasuke pairs up with her in battles, and he uses her brute force along with his own skills to defeat enemies that are much stronger than them individually.
Amaterasu, the sun goddess in Japanese mythology. Her story begins with her residing in the heavens. However, due to the actions of her unruly brother Susanoo, she became so distraught that she withdrew into a cave. This led to a great darkness covering the earth. The gods were desperate to bring her back. They set up a mirror and other attractions outside the cave. When Amaterasu peeked out to see what was going on, she saw her reflection in the mirror and was intrigued. This moment allowed the other gods to pull her out of the cave, and sunlight once again filled the world. Amaterasu is highly venerated in Shinto as she is seen as the source of life - giving light.
Amaterasu could be portrayed as being attracted to the bright color of lemons, similar to how she is associated with the sun. The lemons' color might remind her of her own power and essence. So, she could be depicted as seeking out lemons for their aesthetic and symbolic value.
If Naruto was obsessed with Amaterasu, his character would change in several ways. Firstly, he would become more secretive as he tries to keep his newfound interest from his friends. He would also start to train more rigorously, sacrificing his free time and time with his friends. His view of the world might change too. Instead of just seeing the good in people, he might start to see the potential threats in those who could use Amaterasu against the village. His relationships would be strained, especially with those who don't understand his obsession, like Sakura who might worry about his change in behavior. As he gets deeper into his study of Amaterasu, he could even start to question his own values and what it means to have such a powerful and potentially dangerous ability.
Well, if Naruto had the Phenex power and could use Amaterasu in the Susanoo, it would be an insanely powerful combination. The Phenex power might enhance the already intense Amaterasu flames within the Susanoo. Naruto's chakra control would play a huge role in how he wields this newfound power. He could potentially use it to create massive destruction or for defensive purposes, like creating a shield of super - hot Amaterasu - laced Susanoo around himself or his allies.
In a 'amaterasu x waka fanfiction', the author might play around with the cultural backgrounds of these characters. Amaterasu is often associated with Japanese mythology. So the story could draw on that rich mythology while also developing Waka's character in a way that fits into this world. Maybe it shows how Waka respects and learns from Amaterasu's divine nature, and in turn, Amaterasu discovers something new about the mortal world through Waka.