Who could be the main villain in a Ben 10 Dracula fanfic?

Albedo could be a great main villain. Since he's always been jealous of Ben and his Omnitrix, if he got his hands on the Nemetrix, he could try to use it to create chaos. He might modify the Nemetrix to turn Ben's alien forms against him or use it to enhance his own powers in a twisted way.

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.

The Highbreed could also serve as the main villain. They are a powerful and xenophobic race in the Ben 10 universe. In a crossover, they might view the Justice League's world as a place to expand their territory. They could use their advanced technology and large numbers to attack. Ben would have to convince the Justice League that the Highbreed are a serious threat and together they would need to find a way to stop the Highbreed's invasion, perhaps by using Ben's alien forms like Upgrade to hack into their technology and the Justice League's strategic planning.

Maybe it's a human villain who made a deal with the aliens during the space war. Now that Ben is back, this human villain sees him as a threat to his new - found power and plans to eliminate him. The villain could be a power - hungry scientist or a military leader gone bad.

Vilgax could be a great antagonist. He could hack into the gaming systems to try and defeat Ben in a virtual world where the rules are different. He might use his advanced technology to create digital versions of his minions to attack Ben.

It could be a new alien species that Ben has never encountered before. This species could be territorial and see Ben as a threat to their planet where he's stranded. They constantly try to drive him away or capture him, which makes it difficult for Ben to find a way to leave.

One option could be an alien scientist who is obsessed with the power of the Nemetrix. He wants to study it and use it to create his own super - weapons. He might be from a race that has been at odds with the creators of the Nemetrix for centuries.

Maybe a malevolent scientist who has a grudge against female heroes. He believes that only men should have such powers and sets out to take the Omnitrix from Ben and use it for his own evil purposes. He underestimates Ben because she is a girl but soon realizes his mistake.

Maybe an ancient evil spirit that has been awakened due to some mistake. It targets Ageha because she has a pure and powerful chakra. Naruto, being the hero he is, tries to fight the spirit, but he quickly realizes that he needs Ageha's help as well as the help of all his friends to defeat this powerful foe.

Perhaps an ancient evil spirit that has been awakened by the mixing of the two worlds - Ariel's underwater world and Mowgli's jungle world. This spirit wants to plunge both worlds into darkness. It starts by causing natural disasters in both areas, like huge storms in the ocean and forest fires in the jungle. Ariel and Mowgli must figure out a way to stop this spirit before it's too late, by finding ancient artifacts that can seal the spirit away again.