One idea could be a crossover where Ben Tennyson and Spider - Man team up to stop a common enemy like Doctor Octopus who has somehow gotten his hands on some of the Omnitrix's alien DNA. They could combine their powers and skills to outwit the villain.
I'm not entirely sure as it could be a very specific or fan - made story. But generally in the Ben 10 Ultimate Alien series, Ben Tennyson has a new Omnitrix which gives him access to ultimate forms of his aliens. The big story might involve him facing new villains, protecting the Earth and the galaxy, and dealing with the consequences of using his powers.
I'm not entirely sure about the exact plot details of 'ben 10 ultimate alien the big story'. It might involve Ben Tennyson using his various alien forms to face some big threats and challenges, but that's just a general guess.
One interesting concept could be the clash of different art styles. For example, when a detailed anime - style character meets a more simplistic Western - style cartoon character. It creates a visually striking contrast. Another concept is the melding of different universes' rules. Like in a crossover between a magical cartoon world and a sci - fi one, characters have to adapt to new ways of doing things. Also, the character interactions can be really fun. Imagine a heroic character from one cartoon teaming up with a villain from another just because they share a common enemy in the crossover story.
Well, it depends on how it's written. If it focuses on positive aspects like friendship, adventures, and character development within the Ben 10 universe, it can be appropriate. However, if it involves inappropriate or adult - themed content, then it's not acceptable, especially in a public or general - audience context.
Ben Tennyson is definitely one of the main characters. He's the one with the Omnitrix and can transform into various aliens. Gwen, his cousin, who also has magical powers, might be another main character. And of course, there's Grandpa Max who has been guiding Ben in his adventures.
Ben 10 Ultimate Alien is about Ben Tennyson who has the Omnitrix which allows him to transform into various alien forms. In this series, he has new challenges and enemies. He unlocks ultimate forms of his aliens, which are more powerful. He continues to protect the Earth and the universe from different threats.