Alien X is an obvious choice. With its near - omnipotent powers, it could turn the tide of any space battle. But since it's a very powerful form, it could also be a source of internal conflict for Ben as he has to decide when and if to use it.
The Plumbers could be great characters to include. They could be helping Ben out in space battles, providing backup and useful technology. Characters like Max Tennyson among the Plumbers have a lot of experience and wisdom to offer in such situations.
Definitely Ben Tennyson himself. He's the main character and the one with the Omnitrix. His different alien forms like Heatblast, Four Arms, and XLR8 can add a lot of action and variety to the story.
Gwen is an obvious choice. She can bring her magic skills and her relationship with Ben to the story. Also, Grandpa Max, who has a lot of knowledge and experience that can be useful in the fanfic. Another good character could be Kevin, with his ability to absorb materials and his complex relationship with Ben.
Maybe a story where Ben teams up with some of his alien enemies against a greater threat in space. They could be in a situation where they have to fight a powerful cosmic entity that wants to destroy all known planets. Ben would have to convince his former foes that they need to work together by showing them the magnitude of the danger.
Obviously, Ben is a must - include character as he is the main user of the Omnitrix. Gwen can also be a great addition as she has her own powers and can provide support or be a source of conflict. Grandpa Max is another good character, with his experience and knowledge.
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.
Gwen could be really interesting. She could have developed different powers in a different time period that Ben discovers when he travels back. Also, Grandpa Max in his younger days would be cool. He might have been involved in some secret time - traveling adventures that Ben uncovers. And Vilgax from different points in time could add a lot of drama. Maybe a younger Vilgax who is still learning and more vulnerable, or an older, more powerful Vilgax from a far - off future.
Max Tennyson is a great character to include. He has a lot of wisdom and experience which can add depth to the story. He can be the one to give Ben and Gwen advice during their adventures. Another good character is Kevin Levin. His complex relationship with Ben and Gwen can create interesting plotlines, especially if there are conflicts or reconciliations involved.
Well, it's obvious that Ben and Gwen are the central characters. Ben is the one with the cool Omnitrix. He can turn into aliens like Heatblast or Four Arms. Gwen, his cousin, is no less important. Her magic powers range from creating force fields to shooting energy blasts. Together, they make a great team. Ben brings the alien - powered muscle, and Gwen brings the magic - infused intelligence. They face all kinds of challenges, whether it's an evil alien invasion or a mysterious magical anomaly, and they rely on each other to get through it all.
Evie is a great character to include. She's Mal's best friend and has her own unique style and skills. Her knowledge of fashion could be used in a story, like if they need to create disguises or outfits for a special event in the fanfiction. Also, Jay could be included. His athleticism and thieving skills can add an element of action and adventure. He could be the one who steals a crucial item or gets them out of a tight spot.
Ben Tennyson is obviously a must - as he is the main character. Gwen is also very popular as she has her own powers and often helps Ben. Kevin Levin is another great choice. His ability to absorb materials and his complex relationship with Ben add a lot of depth to the story. Vilgax is a classic villain that makes any fanfiction more exciting. He's powerful and has a long - standing rivalry with Ben.