Who could be the main villain in a 'Ben 10 Justice League crossover fanfiction'?

A good main villain could be Brother Eye. It's a powerful and menacing artificial intelligence. In a crossover, it could have evolved in the future to be even more dangerous. It could pose a threat to both the future world of Batman Beyond and the past era of the Justice League, forcing them to team up to take it down.

In a Ben 10 and Justice League crossover fanfiction, there could be epic battles. Ben could use his alien forms to team up with Superman and take on powerful villains. For example, Ben as Four Arms could help Superman in a physical fight against a huge and strong enemy.

One possible plot could be that the Omnitrix malfunctions and sends Ben 10 to the Justice League's universe. The Justice League initially views Ben as a threat due to his alien forms. But as they learn more about him and the threat of an inter - dimensional villain, they team up. Ben's different alien forms offer unique skills that complement the League's powers, and together they fight the villain to save both universes.

Darkseid as a vampire - like being. He could come to Earth and start turning people into his vampire minions. His already formidable powers combined with vampiric abilities would make him a terrifying foe for the Justice League.

Brainiac would be a great choice. He has advanced technology that could be a huge challenge for the OC gamer. The OC might have to use their gaming knowledge to outwit Brainiac's complex systems and plans. For instance, if Brainiac tries to assimilate the world's knowledge, the OC could use their strategic gaming skills to disrupt his data - collecting devices.

Darkseid would be a great main villain. He's already a powerful and well - known foe in the DC universe. He could be the one who starts collecting the Infinity Stones - like items to gain ultimate power and rule over all universes. His army could also be involved, making it a large - scale war for the Justice League.

It could be Eggman. He might team up with some of the Justice League's villains, like Lex Luthor. Eggman could bring his mechanical creations and knowledge of chaos emeralds, while Luthor provides his strategic mind and resources. Together, they could pose a huge threat to both Sonic and the Justice League.

An evil alien warlord from a far - off galaxy could be a great main villain. He could have an army of powerful alien creatures at his command. He might be after the Omnitrix, Gwen's magic book, and Kevin's Osmosian powers to become all - powerful. His forces could be causing chaos across the universe, and it's up to Ben, Gwen, and Kevin to stop him.

Voldemort could be a main villain. Imagine him getting his hands on some of the Justice League's technology and using it to enhance his dark magic. He could become even more powerful and pose a threat not just to the wizarding world but also to the world the Justice League protects.

Well, I think Batman and Hermione could be main characters. Batman's intelligence and detective skills combined with Hermione's vast knowledge of magic would make for an interesting dynamic. They could be the ones leading the team in strategizing against the common enemies that the crossover would bring. Also, Wonder Woman and Ginny Weasley could be important. Wonder Woman's strength and combat skills paired with Ginny's talent in magic, especially her Bat - Bogey Hex, could make them a formidable duo in the story.