Well, in the fanfic, Anakin's skills would be a huge asset or a threat to the First Order. If he decides to join them, his combat abilities and knowledge of the Force could make the First Order even more powerful. However, if he realizes that they are on a wrong path, like the Sith - influenced path he once walked, he might use his skills to undermine the First Order from within. He could start by influencing the stormtroopers, showing them that there are other ways than blind obedience.
Well, he could either try to take over the First Order with his powerful Force abilities. Maybe he would see it as a new tool to gain more power and control in the galaxy.
Some in the First Order could see him as an opportunity. They might think that his skills and knowledge could be used to strengthen their military might. However, others could be suspicious, especially those who are power - hungry themselves and see Anakin as a rival for leadership within the organization.
The First Order's higher - ups, like General Hux, would likely be suspicious of Anakin. They wouldn't want someone with so much power and an unknown agenda running around. They might try to keep an eye on him, or even plot to get rid of him if they think he's going to disrupt their plans for galactic domination.
Maybe Anakin would be shocked by the advanced technology in the future. He might see flying cars and towering skyscrapers everywhere.
One possible plot could be Anakin going back to a time before his fall to the dark side. He could use his knowledge of the future to prevent certain tragedies. For example, he might stop the Clone Wars from starting, thus saving countless lives. This would also give him a chance to redeem himself and perhaps even change the fate of the Jedi Order.
Well, Padme could try to fight Anakin to stop him from further embracing the dark side. She might use her diplomatic skills and love for him as weapons. For example, she could tell him how their unborn child would grow up without a father if he continued down this path.
In this fanfic, Harry could discover new magical creatures unique to Drumstrang. He may also get into some sort of friendly competition with other students. And who knows, he might even learn some new spells that are not commonly taught at Hogwarts. The change of environment would surely have a big impact on him.
Perhaps in this 'Boruto goes missing fanfic', Boruto is lured away by a mysterious figure who claims to have information about his future or his father Naruto's past. He follows this figure without thinking, only to find himself in a strange and dangerous place. His disappearance then sets off a chain of events in the village. People start to suspect that there might be a traitor among them who helped Boruto disappear. His teammates, like Sarada and Mitsuki, would then start their own investigation to find him, facing not only external threats but also internal doubts and suspicions within the village.
In the 'naruto goes to kumo fanfic', Naruto could be on a mission in Kumo. He might make new friends or enemies. He could also learn new jutsu from the ninjas in Kumo. It could be a great opportunity for him to grow as a ninja and expand his understanding of the ninja world.
In the 'Harry goes to the hospital fanfic', it's possible that Harry is injured during a Quidditch match. He is then rushed to the hospital. There, he could discover a hidden part of the hospital that has some ancient magic stored. He might also have some deep conversations with his friends who come to visit him about their future plans and the current state of the wizarding world.