The story would likely take a very dark turn. Team 7 would probably be hunted by the village. They would become outcasts and have to constantly be on the run. Their relationships with other characters would be completely shattered.
Alternatively, they could be taken in by a powerful enemy who was behind the whole thing. This enemy would use Team 7 for their own purposes, believing that they could be useful tools now that they had proven themselves capable of killing a powerful shinobi like Kakashi.
Maybe they would start to regret their actions and try to find a way to bring Kakashi back. This could lead them on a quest to find some sort of resurrection jutsu or artifact. Along the way, they would face many challenges and also have to deal with their guilt.
In a 'kawaki kills naruto' fanfic, the story would likely take a very dark turn. The characters would be forced to reevaluate their relationships and loyalties. Sasuke, for example, would be deeply affected as Naruto was his closest friend. He might be torn between seeking revenge and trying to understand what drove Kawaki to such an act. The new generation of ninja, like Sarada and Mitsuki, would also be involved in the aftermath. They might be caught in the middle of the conflict between Boruto and Kawaki, trying to find a way to restore peace while dealing with their own feelings of loss and confusion.
The fanfic could explore how the death affects the younger generation in Riverdale. Maybe the kids at school start to form a support group in Betty's name. Or perhaps there are some who try to follow in Betty's footsteps and continue her work for justice, which would create a new dynamic in the town as they face opposition from those who don't want change.
Another motive might be related to some dark power corrupting Team 7. This power could have twisted their minds and made them see Kakashi as an obstacle in their path to achieving ultimate power. It could be something like the curse mark in the original Naruto series but even more powerful and insidious.
Some fans would be really shocked and sad. Kakashi is a very popular character, and his death at the hands of Obito would be a huge blow to many. They might feel angry towards the author for creating such a tragic scenario.
After Harry is knocked out, it could lead to a rift among the students. Some might side with McLaggen, thinking it was an accident, while others would be firmly on Harry's side. The story could then focus on the conflict between these two groups. Hermione might use her intelligence to find a way to wake Harry up and also prove McLaggen's wrong - doing. Ron, on the other hand, would probably be very angry and want to confront McLaggen right away. As the story unfolds, it could also explore the relationships between different characters and how they are affected by this incident.
The power structure would be completely disrupted. There would be no more divine interference in mortal affairs, which could lead to chaos at first as there are no gods to control natural elements like the sea or the sky. But it could also lead to new opportunities for mortals to take control of their own destinies.
After the proposal, they would probably start preparing for their wedding. Ino would be very involved in the planning, choosing the perfect flowers and dress. Naruto would be more focused on making sure all their friends are invited. Their friends would also be excited, and some might even offer to help with the preparations.
Perhaps Naruto's departure would lead to Rias trying to win him back. She could send her servants or allies to find Naruto and try to convince him to return. This would create a series of adventures as Naruto tries to avoid being found while also dealing with his own problems.
The story could progress with them going on a quest. Maybe they are searching for an ancient artifact that has the power to change the fate of the galaxy. Along the way, they would face various obstacles and enemies. Their different perspectives would lead to some interesting decisions on how to handle these situations.
The story could start with Ben arriving in the Marvel universe just as the zombie outbreak begins. He'd be confused at first but quickly realize the danger. He might start by using some of his basic alien forms to test the zombies' weaknesses. As the story progresses, he could meet some of the Marvel heroes who are still alive and form an alliance to find a cure.