Ben Hur is not a true story in the traditional sense. It's a work of fiction that takes cues from history and imagination to craft an engaging tale for the audience.
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.
One idea could be Ben Tennyson using his Omnitrix to team up with Spider - Man. Ben could transform into XLR8 to chase down villains while Spider - Man swings through the city. Another could be having Four Arms help the Hulk in a battle, combining their brute strength. And perhaps Heatblast could join forces with the Human Torch to fight a fire - based villain.
Captain America would be a great addition. His leadership and moral compass could guide Ben in some tough situations. And then there's Wolverine. His healing factor and fierce fighting style would contrast well with Ben's more alien - based combat. They could have some epic battles side by side.
There might be a 'Ben Ten Marvel Fanfic' where Ben meets the X - Men. Imagine Ben showing off his alien forms to the mutants. He could learn from Professor Xavier about controlling his powers better, while also teaching the X - Men some new combat techniques using his alien abilities. For example, Heatblast could help Iceman with his control over heat and cold in a new way.
Team - up and friendship is also a major theme. Ben, coming from his own universe, has to form alliances with Marvel characters. These relationships develop as they face various threats together. For example, Ben might become friends with Iron Man and learn about technology and responsibility from him.
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.
Loki could also be a main antagonist. He could see Ben as an interesting new player in the universe and try to manipulate him for his own gain. Or he might want to use the Omnitrix to cause chaos across the multiverse.