Hermione would probably be very curious about Amaterasu. She would start researching about her in the Hogwarts library and try to understand her powers and her place in the other realm. Ron, on the other hand, might be a bit more cautious and a bit in awe. He would probably make some clumsy attempts at greeting her at first. Harry would be more open - minded. He might share his own experiences of facing powerful forces with Amaterasu and learn from her about her own battles against darkness.
Maybe Amaterasu takes an interest in Harry Potter because she senses his strong magical aura. She decides to bestow some of her powers on him, which changes the way he can perform magic in the wizarding world. This new power could make him a target for dark wizards, like Voldemort, who wants to harness this unique magic for his own evil purposes. So Harry has to learn to control this new power with the help of his friends at Hogwarts while also dealing with the attention from the dark side.
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.
One common theme could be the exploration of their relationship in different mythological settings. Maybe how they interact with other deities in their world.
One common theme could be the clash or harmony of different powers. Since Issei might have his own set of powers and Amaterasu is a significant figure in mythology with her own powers, their interaction in terms of power dynamics can be a theme. For example, how they combine their powers to face a common enemy.
One way to find good 'issei x amaterasu fanfiction' is to ask in relevant fan communities or forums. People who are into the same fandom might be able to point you towards some great works. They may have their own favorites based on the plot, the writing style, or how well the characters are developed in the fanfiction.
You can try looking on fanfiction websites like FanFiction.net or Archive of Our Own. They usually have a large collection of fanfictions, including those related to Naruto and Amaterasu. Just use their search functions and type in 'Naruto x Fem Amaterasu' to see if there are any relevant stories.
It could be a rogue ninja who has also discovered a way to harness the power of Amaterasu in a corrupt way. This ninja might want to use the power to take over the ninja villages and Naruto stands in his way.
One common theme is the power dynamic. Naruto has his ninja powers, and Amaterasu has her divine abilities. How they interact with each other in terms of power, whether it's complementing or conflicting, is often explored. For example, they might combine their powers to defeat a powerful foe.