Well, initially in the fanfic, Ben 10 would be in his own world when he detects some strange energy. Following it, he gets transported to the Marvel Zombies universe. At first, he'd use his alien forms like Diamondhead to shield himself from the attacking zombies. As the story moves forward, he'd start exploring the Marvel world to understand what caused the zombie outbreak. He'd cross paths with characters like Captain America (if not zombified yet) or Iron Man. They'd share knowledge and resources. Ben would then try to use the technology in his Omnitrix to analyze the zombie virus. With each new discovery, they'd get closer to either finding a cure or a way to stop the spread of the zombies, all while facing various challenges and battles.
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.
Well, in a Ben 10 and Marvel Zombies fanfic, a great crossover would involve Ben's Omnitrix getting corrupted by the zombie virus. This could lead to some of his alien forms having zombie - like traits. Also, imagine Ben teaming up with the few remaining non - zombified Marvel heroes like Spider - Man. They could use Ben's shape - shifting abilities and Spider - Man's agility to outwit the zombies.
Wolverine would make an excellent protagonist. His healing factor would give him an edge against the zombies. He's also a loner by nature, so he could be on a solo mission to find out the cause of the zombie outbreak and stop it. He has a lot of combat experience and his adamantium claws would be very effective weapons against the zombified heroes and villains.
A Ben 10 and Marvel fanfic can stand out if it plays with the concept of time and space. Since Ben has access to different alien forms which could potentially mess with the fabric of space - time, and Marvel has characters like Doctor Strange who are masters of time - related magic. You could have a story where Ben accidentally disrupts the space - time continuum in the Marvel universe and has to team up with the Avengers to fix it. This would not only create a unique plot but also allow for some really interesting interactions between the two universes' characters.
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.
It would depend on the writer's intention. If the focus is on Naruto's growth, he could start exploring new jutsu or forms of chakra control. Since he was revived by Madara, there might be some dark elements associated with his revival that he has to overcome. Maybe he has to fight off some sort of curse that came with the revival process. And he would have to do this while still trying to protect the people he cares about.
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.
It could start with Naruto being in a new realm of power, and Deathstroke somehow getting involved in his training. Maybe Naruto is seeking new challenges and Deathstroke offers his expertise. Then, they would start with basic combat training, with Deathstroke pushing Naruto to his limits. As the story progresses, they might face common enemies that require both of their skills to defeat. And Naruto would gradually incorporate Deathstroke's teachings into his own fighting style.
In a fanfic with this scenario, the story would take a dark and twisted path. Harry joining Voldemort would mean that the values he once held dear are now being tossed aside. Voldemort would start to manipulate Harry, perhaps using memories of his parents' death to make him more bitter. The Order of the Phoenix would have to reevaluate their strategies as Harry now knows a great deal about them. And as Harry gets more involved with Voldemort's plans, he might start to see the world in a more cynical way. His magic could also change, becoming darker and more unpredictable as he delves into the dark arts under Voldemort's tutelage. This would lead to a series of events where the line between good and evil becomes blurred for Harry and for the readers.
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.
The story could progress with her sisters using their powers to search for a cure or a way to heal Macy. They might consult with other magical beings or look through ancient books for answers.